Stop one piece in time, yours or theirs (never a king): for 2 of its owner's turns it cannot move, and it cannot be captured. It is simply not here right now.
You draft Time Stop in Buff mode. Activated: you choose when to use it, and using it is your move for that turn.
As a tempo card, it buys time: an extra move, a skip, or a freeze.
“For it, the clock simply stopped.”