The Labyrinth Index (Laundry Files, #9)

by Charles Stross

(Mo’s husband insists that all hotel corridors join up eventually via those doors labelled EMPLOYEES ONLY in a hyperdimensional manifold he calls Hotelspace, but he’s always been a few screws short of a full set, and I’ve long since given up trying to figure him out—not my problem anymore.)

“How much coffee did we have this morning?” Pete asks, suspicion dawning. “All of it!”