A mysterious figure steals a time turner

Criminal Activity

A mysterious figure enters the ministry of magic and steals a time-turner, they disarmed Harry, making them the owner of the elder wand (spoilers in full content)

Ace from the future uses the history box to steal the time turner that will later be used to make the history box, a fixed point in time, future Ace will later let his younger self disarm him, making him the master of death.