An elevator

The door slides open, and to your surprise, it's not a typical garden shed. There are no garden tools or bags of soil. You step into the shed and the interior lights up, probably due to a motion sensor. With the light on, you look around the relatively small shed, and notice a solitary button on the wall. It looks like an elevator button, except there's no arrow pointing up or down, or even a number.

Your finger hoovers over the button, looking outside to see if anyone else is around. There's still no sign of Allison or any of the girls. For a moment, you wonder if you should go find Abby first and ask her about the mysterious elevator, but then you remember that technically, the estate belongs to you now. That includes this mysterious shed and whatever happens if you press the button.

Gulping, you count to 3 in your head before you press the button. It lights up in a dull blue color, and you hear a low hum, like you've triggered some mechanism or engine with the button. The shed door slowly closes, slow enough that you could still change your mind and hop out at the last moment before whatever is about to happen, happens, but you stand still and wait instead. Once the door shuts, you feel the shed around you moving a little, before it starts to descend into the ground at an alarmingly fast pace, so fast that you take a few steps back until your back is against the wall of the shed and you hold onto it with both hands.

It seems like forever before the shed or elevator finally slows down, then it comes to a rest. You hear a click outside the door, like the shed had just docked itself to something. Taking a few deep breaths to compose yourself, you reach for the door and slide it open to the side.