Mysts o' Tyme Marshe
From Monkey Island wiki
The Mysts o' Tyme Marshe is a geographical feature of the interior of Lucre Island. It is an eerie location, full of thick gray mist, dead trees, and the skeletons of old wrecked boats. The water has a distinct pungent smell, and is deep enough that it can only be traversed by boat. The marsh is extremely difficult to navigate without becoming hopelessly lost. Its name comes from the fact that time varies according to location inside the marsh, which can lead to paradoxical events like meeting your future self.
Guybrush Threepwood must navigate the marshes to find Pegnose Pete's home. The only known set of directions are kept at Deadeye Dave's Palace of Prostheses, where they can be retrieved upon discovering Pegnose's pseudonym. The directions look like a train schedule, listing times and cardinal directions. The proper manner to traverse the marshes is to take a clock with on the raft and travel in the direction associated with the time the clock shows.
At one point Guybrush will encounter a double of himself on the other side of a gate. He must avoid a paradox by remembering exactly what the other Guybrush says and does, because later on in his journey, he will be on that side of the gate and need to pass through. At the first encounter Guybrush will receive (among other items) a skeleton key with which he can open the gate; at the second encounter he must pass these items in the same order to the other Guybrush so the gate can be opened for him. The three other items passed from Guybrush to Guybrush are a rope, a revolver (both weapons from the board game Clue (or Cluedo)), and a rubber chicken with a pulley in the middle.