Séance is a very flavorful white enchantment from Dark Ascension that allows you to temporarily bring back creatures from your graveyard as spirits. As mentioned, this is temporary. Séance’s ability triggers at the beginning of each upkeep step. When this ability goes on the stack, the controller of Seance chooses a target creature card in his or her graveyard. When the ability resolves, the targeted card is exiled, a token is put into play and a delayed triggered ability is created. This delayed triggered ability goes on the stack at the beginning of the next end step. When this delayed trigger resolves, the token creature that was put into play will be exiled.

This delayed triggered ability will go on the stack when the next end step begins, regardless of whose turn this is. In most cases, this will happen in the same turn the token was created; however, if a turn ends early before the end step begins (via something like Sundial of the Infinite), the trigger will wait until the next turn’s end step, and will trigger at that point.