Sorcery, 1U (2) Target player reveals his or her hand. Choose an instant or sorcery card from it, and remove that card from the game. As long as the card remains removed from the game, you may play it. At end of turn, if you haven't played the card, return it to its owner's hand.1
Illus. Don Hazeltine
The card is revealed to all players while it is removed from the game. [DeLaney 2000/05/29]
You can play the instant or sorcery during the end of turn step after you put the "at end of turn" trigger on the stack, as long as you do so before that trigger resolves. [Prophecy FAQ 2000/05/25]
The card may only be played once. Once it is announced and put on the stack, the card is no longer removed from the game and the effect of Psychic Theft ends. [D'Angelo 2000/07/06]