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diff --git a/assets/sprites/switch-closed.png b/assets/sprites/switch-closed.png
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diff --git a/components/pairs.go b/components/pairs.go
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--- /dev/null
+++ b/components/pairs.go
@@ -0,0 +1,38 @@
+package components
+
+import (
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/mlange-42/arche/ecs"
+)
+
+// the  Bond components  binds  two different  entities together,  one
+// manipulates the other
+type Bond struct {
+	ecs.Relation
+}
+
+// A door  has a relation  to a switch  using the Bond  component. The
+// Switch opens or  closes the door, depending on  player actions. The
+// door itself is merely dump and just does what being told.
+
+type Door struct {
+	IsOpen      bool
+	OpenSprite  *ebiten.Image
+	CloseSprite *ebiten.Image
+}
+
+func (door *Door) Open() *ebiten.Image {
+	return door.OpenSprite
+}
+
+func (door *Door) Close() *ebiten.Image {
+	return door.CloseSprite
+}
+
+// the switch is being activated when  the player runs over it, it can
+// either use a timeout or just stay in its switching position
+type Switch struct {
+	IsOpen      bool
+	OpenSprite  *ebiten.Image
+	CloseSprite *ebiten.Image
+}