"Yeah," you conclude, "let's do it."
You and your friends decide to enter under cover of darkness via a storm door leading into the basement. You each pack flashlights, spare batteries, and a few other supplies in mostly empty backpacks. Just before midnight, you gather around the house. The storm door is locked, but Tom easily busts it open with the aid of a small crowbar. He props the door open, then descends the steep steps, leaving you and Janice to follow. You go in next, with Janice behind you. She is starting to say, "Are you sure this will stay open?" as the door falls shut. You gasp, while she lets out a brief scream and Tom mutters a sharp expletive. Janice pushes on the door, first alone and then with your help, but it seems impossible to open from the side you're on.
"Great," Janice says, "just great. This is perfect. Now what do we do?"
"Relax," Tom chimes in, "there are other doors, and we'll be able to unlock them from this side."
Janice lets off a nervous chuckle and says, "Oh, right."
Where do you start?