The Mystery Factory is a special location option during Always be Looting events. It is an interior map not unlike other factory locations you might come across, and contains the usual assortment of rooms, such as the boss room, break room, safe room. The loot you will find in these rooms will likewise be very similar to other factory locations: tool type weapons, golf clubs in the boss room, grenades/pipe bombs in the safe room, food in the break room, etc.

The two major differences are that the factory will contain larger than usual amount of zombies, and a large amount of extra loot of a single type(bullets, medical supply etc).