Then she pulled the trigger the rest of the way and blew her own head off.

THE DOORS DIDN’T OPEN FOR A LONG TIME. MAYBE SOMEONE had used the emergency intercom or maybe the conductor had heard the shot. But whatever, the system went into full-on lockdown mode. It was undoubtedly something they rehearsed. And the procedure made a lot of sense. Better that a crazed gunman was contained in a single car, rather than being allowed to run around all over town.

But the waiting wasn’t pleasant. The.357 Magnum round was invented in 1935. Magnum is Latin for big. Heavier bullet, and a lot more propellant charge. Technically the propellant charge does not explode. It deflagrates, which is a chemical process halfway between burning and exploding. The idea is to create a huge bubble of hot gas that accelerates the bullet down the barrel, like a pent-up spring. Normally the gas follows the bullet out of the muzzle and sets fire to the oxygen in the air close by. Hence muzzle flash. But with a hard contact shot to the head like passenger number four had chosen, the bullet makes a hole in the skin and the gas pumps itself straight in after it. It expands violently under the skin and either rips itself a huge star-shaped exit wound, or it blows all the flesh and skin right off the bone and unwraps the skull completely, like peeling a banana upside down.

That was what had happened in this case. The woman’s face was reduced to rags and tatters of bloody flesh hanging off shattered bone. The bullet had travelled vertically through her mouth and had dumped its massive kinetic energy in her brain pan, and the sudden huge pressure had sought relief and found it where the plates of her skull had sealed themselves way back in childhood. They had burst open again and the pressure had pasted three or four large fragments of bone all over the wall above and behind her. One way or the other her head was basically gone. But the graffiti-resistant fibreglass was doing its job. White bone and dark blood and grey tissue were running down the slick surface, not sticking, leaving thin snail trails behind. The woman’s body had collapsed into a slumped position on the bench. Her right index finger was still hooked through the trigger guard. The gun had bounced off her thigh and was resting on the seat next to her.

The sound of the shot was still ringing in my ears. Behind me I could hear muted sounds. I could smell the woman’s blood. I ducked forward and checked her bag. Empty. I unzipped her jacket and opened it up. Nothing there, just a white cotton blouse and the stink of voided bowel and bladder.

I found the emergency panel and called through to the conductor myself. I said, ‘Suicide by gunshot. Last but one car. It’s all over now. We’re secure. No further threat.’ I didn’t want to wait until the NYPD assembled SWAT teams and body armour and rifles and came in all stealthy. That could take a long lime.

I didn’t get a reply from the conductor. But a minute later his voice came through the train PA. He said, ‘Passengers are advised that the doors will remain closed for a few minutes due to an evolving incident.’ He spoke slowly. He was probably reading from a card. His voice was shaky. Not at all like the smooth tones of the Bloomberg anchors.

I took a last look around the car and sat down three feet from the headless corpse and waited.

Whole episodes of TV cop shows could have run before the real-life cops even arrived. DNA could have been extracted and analysed, matches could have been made, perpetrators could have been hunted and caught and tried and sentenced. But eventually six officers came down the stairs. They were in caps and vests and they had drawn their weapons. NYPD patrolmen on the night shift, probably out of the 14th Precinct on West 35th Street, the famous Midtown South. They ran along the platform and started checking the train from the front. I got up again and watched through the windows above the couplers, down the whole length of the train, like peering into a long lit-up stainless steel tunnel. The view got murky farther down, due to dirt and green impurities in the layers of glass. But I could see the cops opening doors car by car, checking, clearing, turning the passengers out and hustling them upstairs to the street. It was a lightly loaded night train and it didn’t take long for them to reach us. They checked through the windows and saw the body and the gun and tensed up. The doors hissed open and they swarmed on board, two through each set of doors. We all raised our hands, like a reflex.

One cop blocked each of the doorways and the other three moved straight towards the dead woman. They stopped and stood off about six feet. Didn’t check for a pulse or any other sign of life. Didn’t hold a mirror under her nose, to check for breathing. Partly because it was obvious she wasn’t breathing, and partly because she didn’t have a nose. The cartilage had torn away, leaving jagged splinters of bone between where the internal pressure had popped her eyeballs out.

A big cop with sergeant’s stripes turned around. He had gone a little pale but was otherwise well into a pretty good impersonation of just another night’s work. He asked, ‘Who saw what happened here?’

There was silence at the front of the car. The Hispanic woman, the man in the NBA shirt, and the African lady. They were all sitting tight and saying nothing. Point eight: a rigid stare ahead.

They were all doing it. If I can’t see you, you can’t see me. The guy in the golf shirt said nothing. So I said, ‘She took the gun out of her bag and shot herself.’

‘Just like that?’

‘More or less.’

‘Why?’

‘How would I know?’

‘Where and when?’

‘On the run-in to the station. Whenever that was.’

The guy processed the information. Suicide by gunshot. The subway was the NYPD’s responsibility. The deceleration zone between 41st and 42nd was the 14th Precinct’s turf. His case. No question. He nodded. Said, ‘OK, please all of you exit the car and wait on the platform. We’ll need names and addresses and statements from you.’

Then he keyed his collar microphone and was answered by a loud blast of static. He answered that in turn with a long stream of codes and numbers. I guessed he was calling for paramedics and an ambulance. After that it would be up to the transportation people to get the car unhooked and cleaned and the schedule back on track. Not difficult, I thought. There was plenty of time before the morning rush hour.

We got out into a gathering crowd on the platform. Transport cops, more regular cops arriving, subway workers clustering all around, Grand Central personnel showing up. Five minutes later an FDNY paramedic crew clattered down the stairs with a gurney. They came through the barrier and stepped on the train and the first-response cops stepped off. I didn’t see what happened after that because the cops started moving through the crowd, looking around, making ready to find a passenger each and walk them away for further inquiries. The big sergeant came for me. I had answered his questions on the train. Therefore he made me first in line. He led me deep into the station and put me in a hot stale white-tiled room that could have been part of the transport police facility. He sal me down alone in a wooden chair and asked me for my name.

‘Jack Reacher,’ I said.

He wrote it down and didn’t speak again. Just hung around in the doorway and watched me. And waited. For a detective to show up, I guessed.