When Hilda Spellman buys a clock shop, she purchases a magical Lost in Time Clock to sell, believing it to be a normal grandfather clock. The clock acts as a portal through time that regularly throws out people who made a big mistake at some point in their lives and are meant to go back and correct it. The clock can also be used to send oneself through time intentionally.
Attached to the clock was a note that read: "Lost in time clock. Persons who come through this clock are lost in time. Whoever opens this portal must assist the time traveler or be turned into a clock themselves. No excuses, no exceptions, this means you."