diff --git a/sdcard/layouts/shift.lua b/sdcard/layouts/shift.lua
index dc486bc..241e4b0 100644
--- a/sdcard/layouts/shift.lua
+++ b/sdcard/layouts/shift.lua
@@ -46,6 +46,10 @@ SHIFT   →LAYOUT  🔆BRIGHT
 
 ]]--
 
+shift.KEY_SHIFT = 11
+shift.KEY_LAYOUT = 8
+shift.KEY_BRIGHTNESS = 5
+
 function shift.grab(key)
   mb.grab("shift-shifted")
 end
@@ -70,15 +74,15 @@ end
 shift.keymap = {
   name="shift",
   permanent=true,
-  [11] = {c={r=1, g=1, b=1}, press=shift.grab, release=shift.release},
+  [shift.KEY_SHIFT] = {c={r=1, g=1, b=1}, press=shift.grab, release=shift.release},
 }
 shift.keymap_shifted = {
   name="shift-shifted",
   secondary=true,
-  [11] = {c={r=1, g=1, b=1}, press=shift.grab, release=shift.release},
+  [shift.KEY_SHIFT] = {c={r=1, g=1, b=1}, press=shift.grab, release=shift.release},
 
-  [8] = {c={r=0, g=1, b=1}, press=shift.cycle},
-  [5] = {c={r=0.5, g=0.5, b=0.5}, press=shift.brightness}
+  [shift.KEY_LAYOUT] = {c={r=0, g=1, b=1}, press=shift.cycle},
+  [shift.KEY_BRIGHTNESS] = {c={r=0.5, g=0.5, b=0.5}, press=shift.brightness}
 }
 
 mb.register_keymap(shift.keymap)
diff --git a/sdcard/snippets/routehandlers.lua b/sdcard/snippets/routehandlers.lua
index 5dda270..8a1c242 100644
--- a/sdcard/snippets/routehandlers.lua
+++ b/sdcard/snippets/routehandlers.lua
@@ -18,60 +18,61 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
-]]--
+]] --
 
 -- This all-key, central key router forwards Keybow key events to
 -- their correct handlers, depending on which keyboard layout currently
 -- is active.
 function mb.route(keyno, pressed)
-  local keydef
-  -- Checks for a keymap grab being enforced at this time...
-  if mb.grab_keymap then
-    print("routing GRABBED key")
-    keydef = mb.grab_keymap[keyno]
-  else
-    -- Checks for key in permanent keymaps first...
-    for name, keymap in pairs(mb.keymaps) do
-      if keymap.permanent then
-        keydef = keymap[keyno]
-        if keydef then; break; end
-      end
+    local keydef
+    -- Checks for a keymap grab being enforced at this time...
+    if mb.grab_keymap then
+        keydef = mb.grab_keymap[keyno]
+    else
+        -- Checks for key in permanent keymaps first...
+        for name, keymap in pairs(mb.keymaps) do
+            if keymap.permanent then
+                keydef = keymap[keyno]
+                if keydef then
+                    break
+                end
+            end
+        end
+        -- Checks for key in current keymap if no persistent key was found yet.
+        if not keydef and mb.current_keymap then
+          keydef = mb.current_keymap[keyno]
+        end
     end
-    -- Checks for key in current keymap if no persistent key was found yet.
-    if not keydef and mb.current_keymap then
-      keydef = mb.current_keymap[keyno]
-    end
-  end
 
-  -- Bails out if no key definition to route to could be found.
-  if not keydef then; return; end
+    -- Bails out if no key definition to route to could be found.
+    if not keydef then
+        return
+    end
 
-  --
-  if pressed then
-    for led = 0, 11 do
-      if led ~= keyno then; mb.led(led, {r=0, g=0, b=0}); end
+    -- We found a route, so we need to call its associated handler and
+    -- also handle the LED lightshow.
+    if pressed then
+        for led = 0, 11 do
+            if led ~= keyno then
+                mb.led(led, {r = 0, g = 0, b = 0})
+            end
+        end
+        if keydef.press then
+            keydef.press(keyno)
+        end
+    else
+        if keydef.release then
+            keydef.release(keyno)
+        end
+          mb.activate_leds()
     end
-    if keydef.press then
-      keydef.press(keyno)
-    end
-  else
-    if keydef.release then
-      keydef.release(keyno)
-    end
-    mb.activate_leds()
-  end
 end
 
 -- Routes all keybow key handling through our central key router
-function handle_key_00(pressed); mb.route(0, pressed); end
-function handle_key_01(pressed); mb.route(1, pressed); end
-function handle_key_02(pressed); mb.route(2, pressed); end
-function handle_key_03(pressed); mb.route(3, pressed); end
-function handle_key_04(pressed); mb.route(4, pressed); end
-function handle_key_05(pressed); mb.route(5, pressed); end
-function handle_key_06(pressed); mb.route(6, pressed); end
-function handle_key_07(pressed); mb.route(7, pressed); end
-function handle_key_08(pressed); mb.route(8, pressed); end
-function handle_key_09(pressed); mb.route(9, pressed); end
-function handle_key_10(pressed); mb.route(10, pressed); end
-function handle_key_11(pressed); mb.route(11, pressed); end
+-- by creating the required set of global handler functions expected
+-- by the Keybow firmware.
+for keyno = 0, 11 do
+    _G[string.format("handle_key_%02d", keyno)] = function(pressed)
+        mb.route(keyno, pressed)
+    end
+end
diff --git a/spec/keybowhandler.lua b/spec/keybowhandler.lua
new file mode 100644
index 0000000..3b387c3
--- /dev/null
+++ b/spec/keybowhandler.lua
@@ -0,0 +1,43 @@
+--[[
+Copyright 2019 Harald Albrecht
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+]]--
+
+kbh = {} -- module
+
+-- Convenience: returns the name of a Keybow key handler function.
+function kbh.handler_name(keyno)
+    return string.format("handle_key_%02d", keyno)
+end
+
+-- Convenience: calls Keybow key handler by key number instead of name.
+function kbh.handle_key(keyno, pressed)
+    _G[kbh.handler_name(keyno)](pressed)
+end
+
+-- Convenience: taps a Keybow key, triggering the corresponding key handler
+-- twice.
+function kbh.tap(keyno)
+    local h = _G[kbh.handler_name(keyno)]
+    h(true)
+    h(false)
+end
+
+return kbh -- module
diff --git a/spec/keybowhandler_spec.lua b/spec/keybowhandler_spec.lua
new file mode 100644
index 0000000..c3f3b38
--- /dev/null
+++ b/spec/keybowhandler_spec.lua
@@ -0,0 +1,69 @@
+--[[
+Copyright 2019 Harald Albrecht
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+]]--
+
+local kbh = require("spec/keybowhandler")
+
+describe("Keybow keyhandler", function()
+
+    it("returns proper Keybow handler name", function()
+        assert.equals(kbh.handler_name(0), "handle_key_00")
+    end)
+
+    it("calls correct Keybow key handler", function()
+        stub(_G, "handle_key_00")
+        stub(_G, "handle_key_01")
+
+        kbh.handle_key(0, true)
+        assert.stub(handle_key_00).was.called(1)
+        assert.stub(handle_key_00).was.called_with(true)
+        assert.stub(handle_key_01).was_not.called()
+
+        handle_key_00:revert()
+        handle_key_01:revert()
+    end)
+
+    describe("wrapped Keybow key handler 00", function()
+
+        local old
+        local seq
+
+        before_each(function()
+            old = _G.handle_key_00
+            seq = {}
+            _G.handle_key_00 = function(pressed)
+                table.insert(seq, pressed)
+            end
+        end)
+
+        after_each(function()
+            _G.handle_key_00 = old
+        end)
+
+        it("taps Keybow key handlers", function()
+            kbh.tap(0)
+            assert.equals(#seq, 2)
+            assert.same(seq, {true, false})
+        end)
+    
+    end)
+
+end)
diff --git a/spec/multibow_spec.lua b/spec/multibow_spec.lua
index bc706be..9760b8e 100644
--- a/spec/multibow_spec.lua
+++ b/spec/multibow_spec.lua
@@ -25,7 +25,7 @@ require "mocked-keybow"
 describe("multibow", function()
 
     -- ensure to get a fresh multibow module instance each time we run
-    -- an isolated test...
+    -- an isolated, nope, insulated test...
     local mb
 
     before_each(function()
@@ -80,12 +80,14 @@ describe("multibow", function()
     insl(function()
         it("sets up multibow, activates lights", function()
             local s = spy.on(_G, "setup")
+            local al = spy.on(mb, "activate_leds")
+            
             _G.setup()
             assert.spy(s).was.called(1)
-
-            local al = spy.on(mb, "activate_leds")
-            _G.setup()
             assert.spy(al).was.called(1)
+
+            s:revert()
+            al:revert()
         end)
     end)
 
diff --git a/spec/routehandlers_spec.lua b/spec/routehandlers_spec.lua
index 772c50e..1d36f74 100644
--- a/spec/routehandlers_spec.lua
+++ b/spec/routehandlers_spec.lua
@@ -21,6 +21,7 @@ SOFTWARE.
 ]]--
 
 require "mocked-keybow"
+local kbh = require("spec/keybowhandler")
 
 describe("routehandlers", function()
 
@@ -33,8 +34,15 @@ describe("routehandlers", function()
         prim_key_release=function(key) end,
         prim_otherkey_press=function(key) end,
         prim_otherkey_release=function(key) end,
+
+        sec_key_press=function(key) end,
+        sec_key_release=function(key) end,
+        
         perm_key_press=function(key) end,
         perm_key_release=function(key) end,
+        
+        grab_key_press=function(key) end,
+        grab_key_release=function(key) end,
     })
 
     local primary_keymap = {
@@ -42,11 +50,20 @@ describe("routehandlers", function()
         [0]={press=spies.prim_key_press, release=spies.prim_key_release},
         [1]={press=spies.prim_otherkey_press, release=spies.prim_otherkey_release},
     }
+    local secondary_keymap = {
+        name="test-secondary",
+        secondary=true,
+        [0]={press=spies.sec_key_press, release=spies.sec_key_release},
+    }
     local permanent_keymap = {
         name="permanent",
         permanent=true,
         [0]={press=spies.perm_key_press, release=spies.perm_key_release}
     }
+    local grab_keymap = {
+        name="grab",
+        [0]={press=spies.grab_key_press, release=spies.grab_key_release}
+    }
 
     before_each(function()
         require("keybow")
@@ -58,21 +75,64 @@ describe("routehandlers", function()
     end)
 
     insl(function()
+
         it("defines all Keybow key handlers for routing", function()
             for keyno = 0, 11 do
                 assert.is_function(_G[string.format("handle_key_%02d", keyno)])
             end
         end)
+
+        it("calls routing handler with correct key number", function()
+            stub(mb, "route")
+            for keyno = 0, 11 do
+                mb.route:clear()
+                kbh.handle_key(keyno, true)
+                assert.stub(mb.route).was.called(1)
+                assert.stub(mb.route).was.called_with(keyno, true)
+                mb.route:clear()
+                kbh.handle_key(keyno, false)
+                assert.stub(mb.route).was.called(1)
+                assert.stub(mb.route).was.called_with(keyno, false)
+            end
+            mb.route:revert()
+        end)
+
     end)
 
     insl(function()
 
-        it("routes key press to primary keymap", function()
+        it("doesn't fail for unroutable keys", function()
+            kbh.handle_key(0, true)
+            kbh.handle_key(0, false)
+        end)
+
+        -- start with secondary keymap only :)
+        it("doesn't route a key press to a registered secondary keymap without activation", function()
+            assert.is_not_truthy(secondary_keymap.permanent)
+            assert.is_truthy(secondary_keymap.secondary)
+            mb.register_keymap(secondary_keymap)
+
+            assert.spy(spies.sec_key_press).was_not.called() -- just a safety guard
+            kbh.handle_key(0, true)
+            assert.spy(spies.sec_key_press).was_not.called()
+        end)
+
+        it("routes key press to activated secondary keymap", function()
+            mb.activate_keymap(secondary_keymap.name)
+
+            kbh.handle_key(0, true)
+            assert.spy(spies.sec_key_press).was.called(1)
+            assert.spy(spies.sec_key_press).was.called_with(0)
+        end)
+
+        -- throw in a primary keymap
+        it("routes key press to primary keymap, but not to secondary", function()
             assert.is_not_truthy(primary_keymap.permanent or primary_keymap.secondary)
             mb.register_keymap(primary_keymap)
+            mb.activate_keymap(primary_keymap.name)
 
             assert.spy(spies.prim_key_press).was_not.called() -- just a safety guard
-            handle_key_00(true)
+            kbh.handle_key(0, true)
             assert.spy(spies.prim_key_press).was.called(1)
             assert.spy(spies.prim_key_press).was.called_with(0)
             assert.spy(spies.prim_key_release).was_not.called()
@@ -80,18 +140,19 @@ describe("routehandlers", function()
 
         it("routes key release to primary keymap", function()
             assert.spy(spies.prim_key_press).was_not.called() -- just a safety guard
-            handle_key_00(false)
+            kbh.handle_key(0, false)
             assert.spy(spies.prim_key_press).was_not.called()
             assert.spy(spies.prim_key_release).was.called(1)
             assert.spy(spies.prim_key_release).was.called_with(0)
         end)
 
+        -- adds a permanent keymap on top
         it("routes with priority key press/release to permanent key", function()
             assert.is_truthy(permanent_keymap.permanent)
             assert.is_not_truthy(permanent_keymap.secondary)
             mb.register_keymap(permanent_keymap)
 
-            handle_key_00(true)
+            kbh.handle_key(0, true)
             assert.spy(spies.perm_key_press).was.called(1)
             assert.spy(spies.perm_key_press).was.called_with(0)
             assert.spy(spies.perm_key_release).was_not.called()
@@ -101,12 +162,29 @@ describe("routehandlers", function()
 
         it("correctly routes key press to un-overlaid primary key 2", function()
             assert.spy(spies.prim_otherkey_press).was_not_called()
-            handle_key_01(true)
+            kbh.handle_key(1, true)
             assert.spy(spies.prim_otherkey_press).was.called(1)
             assert.spy(spies.prim_otherkey_press).was.called_with(1)
         end)
 
+        -- and finally adds a grab keymap, what a mess!
+        it("routes to grab keymap", function()
+            mb.register_keymap(grab_keymap)
+            mb.grab(grab_keymap.name)
+
+            assert.spy(spies.grab_key_press).was.called(0)
+            kbh.handle_key(0, true)
+            assert.spy(spies.grab_key_press).was.called(1)
+            assert.spy(spies.grab_key_press).was.called_with(0)
+
+            spies.grab_key_press:clear()
+            mb.ungrab()
+            kbh.handle_key(0, true)
+            assert.spy(spies.grab_key_press).was.called(0)
+            assert.spy(spies.perm_key_press).was.called(1)
+            assert.spy(spies.prim_key_press).was.called(0)
+        end)
+
     end)
 
-
 end)
diff --git a/spec/shift_spec.lua b/spec/shift_spec.lua
new file mode 100644
index 0000000..32e9791
--- /dev/null
+++ b/spec/shift_spec.lua
@@ -0,0 +1,120 @@
+--[[
+Copyright 2019 Harald Albrecht
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+]]--
+
+require "mocked-keybow"
+require "snippets/multibow"
+local kbh = require("spec/keybowhandler")
+
+describe("SHIFT multibow keymap", function()
+
+    local mb = require("snippets/multibow")
+
+    insl(function()
+
+        it("installs the SHIFT keymap", function()
+            -- Sanity check that there are no registered keymaps yet.
+            assert.is.equal(#mb.registered_keymaps(), 0)
+
+            local shift = require("layouts/shift")
+            assert.is_not_nil(shift) -- we're going slightly over the top here...
+            assert.is_not_nil(shift.keymap)
+
+            -- SHIFT must register exactly two keymaps, a primary and a secondary one.
+            local kms = mb.registered_keymaps()
+            assert.is.equal(#kms, 2)
+            for idx, keymap in ipairs(kms) do
+                if keymap == "shift" then
+                    assert.is_falsy(keymap.permanent)
+                    assert.is_falsy(keymap.secondary)
+                elseif keymap == "shift-shifted" then
+                    assert.is_falsy(keymap.permanent)
+                    assert.is_true(keymap.secondary)
+                end
+            end
+        end)
+
+    end)
+
+    insl(function()
+
+        -- ensure to get a fresh SHIFT layout instance each time we run
+        -- an isolated, erm, insulated test.
+        local shift
+
+        before_each(function()
+            shift = require("layouts/shift")
+        end)
+
+        it("SHIFT grabs", function()
+            spy.on(mb, "grab")
+            spy.on(mb, "ungrab")
+
+            -- route in the SHIFT permanent keymap
+            kbh.handle_key(shift.KEY_SHIFT, true)
+            assert.spy(mb.grab).was.called(1)
+            assert.spy(mb.grab).was.called_with(shift.keymap_shifted.name)
+
+            -- route in the shifted(!) SHIFT keymap, so this checks
+            -- that we ungrab correctly
+            mb.grab:clear()
+            kbh.handle_key(shift.KEY_SHIFT, false)
+            assert.spy(mb.grab).was_not.called()
+            assert.spy(mb.ungrab).was.called(1)
+
+            mb.grab:revert()
+            mb.ungrab:revert()
+        end)
+
+        describe("while SHIFTed", function()
+
+            before_each(function()
+                kbh.handle_key(shift.KEY_SHIFT, true)
+            end)
+
+            after_each(function()
+                kbh.handle_key(shift.KEY_SHIFT, false)
+            end)
+
+            it("cycles primary keymaps", function()
+                stub(mb, "cycle_primary_keymaps")
+
+                kbh.tap(shift.KEY_LAYOUT)
+                assert.stub(mb.cycle_primary_keymaps).was.called(1)
+
+                mb.cycle_primary_keymaps:revert()
+            end)
+
+            it("changes brightness", function()
+                stub(mb, "set_brightness")
+
+                kbh.tap(shift.KEY_BRIGHTNESS)
+                kbh.tap(shift.KEY_BRIGHTNESS)
+                assert.stub(mb.set_brightness).was.called(2)
+
+                mb.set_brightness:revert()
+            end)
+
+        end)
+
+    end)
+
+end)