Chapter One

The first two levels are ordinary on purpose. You cannot feel a rule break until you know which rule you expected.

• 1The Ordinary KitchenClassical rulesAn ordinary morning. Push the crate onto the floor plate to hold the hatch open, then go get the fish.
• 2Two BowlsNot knowing yetBreakfast is under one of the two covers. Nothing strange here: the fish is already in one bowl. You simply have not looked.
• 3The Strange DoorSuperpositionThe glowing arch does something to a cat. Walk into it and see. Then get to the fish.
• 4Two Plates at OnceUsing both outcomesThe fish tank is bolted shut. Both floor plates must be held down at the same moment. There is only one cat.
• 5The CameraMeasurementA camera watches the corridor. Cameras do not care whether anyone is looking at the screen. Walk past it and find out what it does.
• 6A Question of TimingWhen to measureThe same plates and latch return, but the way out runs past a camera. The order matters.
• 7Two RoomsOutcomes move togetherTwo rooms, side by side, one plate in each. Every possible outcome of the cat obeys exactly the same step you take.
• 8Schrödinger's PlaygroundEverything at onceCrate, plates, latch, camera, fish. Everything you have learned, in one garden. Both plates must be down together to spring the latch.