"So there's likely to be some of this on his clothing?"

"Pants leg and shoes for certain, until he cleans them. Look here," he said, and my eyes followed the tip of the pen he was using as a pointer. Outlined on the light gray paint of the door to 3B was another bloody design. "That's hers, Alex. She must have braced herself with one foot against that panel to push the guy off. She put up a fierce struggle."

I could make out the V-shaped tip of a woman's shoe sole, and inches lower the circular mark that confirmed it was a pump rather than a flat.

"High heels and all, she did pretty well for herself. Just lucky." The uniformed cop who had been assigned to safeguard the crime scene for the past twenty-four hours spoke to Mercer as he straightened up.

"That's what we're calling it now when someone resists a rapist and ends up in the intensive care unit with a few holes in her chest and a collapsed lung?"

"Sorry, Ms. Cooper. I mean the girl is fortunate to be alive. You know she went DOA when they pulled up to the docking bay at the emergency room?"

Mercer had told me that. Annika Jelt had stopped breathing on the short ride to New York Hospital. The cops who were dispatched to a neighbor's 911 call reporting screams in the stairwell knew there was no time to wait for an ambulance. The young officer who carried the victim down to the patrol car had served in the army reserves as a medic during the war in Iraq. Annika owed her life to the fact that he revived her in the backseat of the RMP, on the way to the ER, before she was rushed into surgery to inflate her lung and stanch the bleeding.

Mercer led the way down the staircase. The traces of black finger-print dust on the banister and walls reminded me that the Crime Scene Unit had done a thorough workup of the building when they were summoned by Mercer, shortly after the 3A.M. attack on a frigid morning in late January.