"Yes Klaus." Max says. He looks almost frantic with anticipation. Keeping him calm while they wait for the cultists to arrive could be difficult...
Klaus takes out his knife, and then looks anxiously up and down the alley. No one in sight. He slides the knife between the window and the frame, and gives it a shove.
[Strength test! dice roll =3 = pass]
The catch breaks at once, and the window comes open with a small popping sound. Klaus looks around again, but no one seems to have noticed.
Max insists on going in first. He slips through the gap easily. "No one's here, Klaus," he hisses, "come on in." Klaus follows him. He gets halfway through the window, and then becomes stuck! For a few moments he's trapped there, imagining knife wielding thugs stabbing his unprotected backside... but Max does his best to pull him through, and he soon gets free and enters the warehouse. He sighs with relief, making sure he closes the window behind him so as to leave no sign.
The ground floor of the warehouse is one large room. There's a staircase in the corner near the door. There are a few crates scattered around in the back half, but a large space has been cleared towards the front. Max hurries off to the stairs, already starting to climb them before Klaus can stop him. Klaus follows him. Upstairs is a loading area near the upper door, and three storerooms. All of these are empty.
Map!

[Ignore the pentagram! It's not there yet... but it will be, later]