C1816 Climbing relation

Several lamps were lit in a small dark room, and one of them flickered out.

Seeing this, the young man hurriedly ran out of the basement and muttered a few words to the gatekeeper outside. Then, he returned to the front of the house and observed the lights inside.

The gatekeeper went into the adjoining guardroom and dialed the number on his desk. After a few seconds, he hung up