“He’ll start another slide!” the foreman wailed in despair. “Run, boys! Run for it.”

Bell scrambled up onto the slope. The man had reached the opening and was flailing away with the pick, trying to make it wide enough to fit through. Broken rock rolled down at Bell. The hole suddenly opened wider, and the man started scrambling up through it. Bell took one of the throwing knifes and hurled it overhand.

The blade flew true to its target and stuck in the heel of the man’s boot as he disappeared up the hole. Bell scrambled after him. Then the rock around the hole separated in a giant sheet of stone that slid down the slope, hurtled past Bell, and crashed to the tunnel floor. The impact shook Bell loose and sent him sliding after it. He hit bottom and barely had time to move aside as a slab of rock half a block long broke off and thundered into the tunnel.

It left in its wake a jagged slope that Bell climbed as easily as a flight of stairs. He emerged at the corner of Fourth Avenue and Thirty-seventh Street just in time to see a full block of brownstone mansions shaking as if in an earthquake. A chasm opened in the sidewalk. The front walls separated from the brownstones and plunged into the subway tunnel.

Isaac Bell could see into the front rooms of the mansions as if he were at the theater watching a play on a stage. The occupants ran like actors who were exiting upstage as fast as they could. Bell ran to help. Motion caught his eye a short block across Thirty-seventh Street. A train on the tracks elevated above Third Avenue was accelerating downtown. Clinging to the back of the rear car was the man in the long coat, and as the El disappeared behind the buildings, he waved good-bye to Isaac Bell.

•   •   •

“HE GOT AWAY,” Bell reported to Joseph Van Dorn.

The Boss was seething.

“What happened to the young lady I ordered you to follow?”

“I lost sight of Mary in a riot. I was looking for her at the Tombs when I ran into him.”

“Was she arrested?”

“The police arrested a hundred women, so I thought I might find her there. But she was not among them.”

“The police,” growled Van Dorn. “Speaking of the police, I just had an unpleasant conversation by telephone with a deputy commissioner who informed me that his patrolmen received reports from the subway contractor that you were present at the street collapse. Apparently, there is speculation that you caused it.”