The monocle is an item found in Alice is Dead, formerly belonging to the Caterpillar. It can be used to read messages written in invisible ink. In the past, the Rabbit thought the monocle was fake after being cheated by the Caterpillar in a game of cards. However, after killing the Caterpillar in Wonderland Forest, he can use it to read things written on the walls of the Hole, including cryptic messages and the combination to the Rabbit's briefcase.