"An unassuming hand mirror.
Something seems off about it."
The Hand Mirror is an item found in Prisoners of the Elder One. It is found in the dresser in the Dirty Room, opened with the Crowbar, and teleports Erik (and whoever else looks at it) to the Nexus. This makes the Hand Mirror perhaps the most important item in the game, or at least the most useful. Using it on Camelia after attempting to clean with her will also teleport her, letting her clear the boulder blocking the Nexus Crypt. This, the Mirror, and the Mirror Shard can also be used to get through the lasers guarding the Yellow Gem.