Locking Key

Wondrous item, uncommon

You can use an action to lock an unlocked door with this key, provided the door has a keyhole. If the door has a functioning mundane lock, the door is then locked using its normal statistics and DC to pick it. If the door doesn't have a functioning lock, it's then magically locked (DC 15); it remains locked in this way for 24 hours or until the door is opened by magical or mundane means. A door that's magically locked using this key can also be opened by it.

And with that, I was never here.