Black Monarch's Treasure Trove

This sleek black and silver fortress is the perfect place to hide tiny treasures. Open the doors, and you'll find a hidden compartment where you can tuck away a trinket or two. Close the doors and turn the silver knob. The next time someone opens the fortress's doors (without turning the knob again), they'll get a spectral surprise! Your treasure will remain hidden, and the unfriendly ghost will give would-be thieves a scare!

Inspired by Black Monarch's Ghost (6034).