Hourglass of Imprisonment

When activated, this item entraps a monster in an extra-dimensional space for three rounds. There is no saving throw to resist the effect. Once used, the Hourglass will vanish.

During those three rounds, the party is free to act however they want. They could explore the room, heal, buff, or whatever strikes their fancy. At the end of the three rounds, the monster will reappear exactly where it was before being shunted to the extra-dimensional space. Though it cannot interact with the players or room in any way, the monster is also free to act during those three rounds and may have a nasty surprise in store for the party when it returns. Initiative is re-rolled when the monster returns.