Schiller walked up to the door of Room 1900. This time, the door was not open; on the contrary, it was shut tight. He tried the handle, but it would not turn. He crouched down to peer through the gap beneath the door, but he could see nothing.
He took out another sticky note and tried to slide it through the gap, but something seemed to be blocking it. The front edge of the note crumpled against the obstruction, yet it would not go in at all.
The gap was too narrow even for a finger. The hotel's facilities were fairly modern, using key cards rather than keys, so there was no keyhole to look through, much less any way to pick the lock.
After thinking for a moment, Schiller's gaze fell on the plaque on Room 1900's door. What was strange was that only the two upper screws remained on the plaque. The two lower screws had vanished without a trace.
Schiller turned to look at Room 1901 across the hall and confirmed that its plaque was indeed secured by four screws, not two. So where had the two screws from Room 1900 gone?
All the plaques looked identical, so it was possible that they had been switched. But could these screws really be removed by ordinary means?
Schiller walked over and first touched a screw with his hand. Nothing happened. He then gently pried at it with his pen and found that it would not budge either. Still, with a screwdriver, it should have been possible to unscrew it.
Schiller did not have a screwdriver, but he did have a knife. He opened his trench coat and took out the thin-looking knife from an inner pocket. It was actually forged from Sound-absorbing Vibranium.
The greatest advantage of this