A gasoline engine started and a gear engaged and the gate was driven back. A minute later the last of the cars was inside the compound and the gear reversed and the gate closed again.

Peterson let Reacher out at Janet Salter’s house. It was his new default destination, night and day. He crunched up the driveway and the woman cop from the hallway let him in. Janet Salter was in the library, in her usual chair, in a pool of light, reading. The other woman cop was at the window, with her back to the room. Situation normal. All quiet.

Janet Salter held up her book and said, ‘I’m reading Sherlock Holmes.’

Reacher said, ‘The dog that didn’t bark in the night?’

‘Exactly.’

‘I already thought about that. Your neighbour lives upwind. Doesn’t mean no one was here, just because her dog didn’t get a sniff.’

‘There’s a companion volume you should see, in the parlour,’ Janet Salter said. She put her book down and got up out of her chair. Reacher followed her to the front room. She closed the door. Didn’t show him a book. Instead she asked, ‘Are the bikers really gone?’

Reacher said, ‘Yes.’

‘Are they coming back?’

‘I don’t think so.’

‘So am I safe now?’

‘Not really.’

‘Why did Chief Holland let them go?’

‘Small town rules,’ Reacher said.

‘Which now mean that if I go ahead and testify as planned, only one man will, as you put it, get nailed.’

‘That’s true.’

‘Which absolutely wasn’t the deal. The idea was to nail them all. Now they’ll just become some other town’s problem.’

‘And then the next, and the next.’

‘It isn’t right.’

‘It’s how things work.’

‘I mean it isn’t right to put me at so much risk for so little reward.’

‘You want to pull out?’

‘Yes, I think I do.’

Five minutes to six in the evening.

Ten hours to go.

JANET SALTER SAT DOWN IN A PARLOUR CHAIR. REACHER CHECKED the view from the window. Nothing there. Just the cop in his car, a good one, his head moving left, moving right, checking the mirror.

Reacher said, ‘I think it’s too late to make a practical difference.’

Janet Salter asked, ‘Why?’

‘You could talk to Holland right now, but Holland can’t talk to the prosecutor before tomorrow, and the prosecutor can’t file the papers until maybe the next day, and the news might take another day to filter through. But the bad guys are in a hurry. That place makes money for them. They can’t afford any downtime.’

Janet Salter said, ‘So I’m in, and I can’t get out?’

‘Hang tough,’ Reacher said. ‘You’ll be OK.’

‘I wouldn’t have been OK last night, except for you. And you won’t be here for ever.’

‘I won’t need to be,’ Reacher said. ‘The bad guys won’t wait for ever.’

Janet Salter went to make dinner. She said cooking relaxed her. The night watch cops got up and came downstairs. The house felt safe. Dark and cold outside, bright and warm inside. Pots and pans on the stove top fogged the kitchen windows, so Reacher prowled between the library and the parlour and the hallway. He saw nothing from the windows except snow and ice and moving shadows. The wind was still blowing. Not ideal conditions for careful surveillance, but Reacher felt the situation was acceptable. Seven cops on the case, with himself as backup. Safe enough.

Then the phone rang.

Reacher was in the hallway at the time and Janet Salter called through from the kitchen and asked him to answer it. It was Peterson. He said, ‘I have something I need you to see.’

‘Where?’

‘At the station, on a computer.’

‘Can you bring it over?’

‘No.’

‘I can’t leave here.’

‘You said we might never hear that siren again. No escapes, no more riots.’

‘An educated guess is still a guess.’

‘I’ll pick you up and bring you straight back.’

‘You can’t promise that. Suppose the siren sounds while I’m over there?’

‘I’ll still bring you back. I swear, on the lives of my children.’

‘You’d get in trouble.’

‘I’ll fight it. And I’ll win.’

‘You should get the department, you know that?’ Reacher said. ‘The sooner the better.’

Peterson arrived five minutes later. He spoke to his people and then he found Janet Salter and told her he was borrowing Reacher for a quarter of an hour. He looked her in the eye and promised her that none of his officers would leave the house until Reacher was back. She was uneasy, but she seemed to believe him. Reacher put his coat on and climbed into Peterson’s car and five minutes after that he was back in the squad room.

Peterson sat down at a desk with a computer and started pointing and clicking and pursing his lips and inhaling and exhaling. He came up with a blank grey square in the middle of the screen. The square had a play arrow laid over its centre portion.

‘Surveillance video,’ Peterson said. ‘From the prison interview room. It’s digital. They e-mail it to us.’

‘OK.’

‘It’s the biker and his lawyer. Earlier this afternoon. We never cancelled the surveillance. You know why?’

‘Why?’

‘Inefficiency.’ Peterson moved the mouse and clicked on the play arrow. The grey square changed to a grainy colour picture of the interview room shot from above. The camera was presumably hidden in a light fixture, on the lawyer’s side of the glass partition. It showed a man in a grey suit sitting forward in his chair with his elbows on the concrete counter and his face a foot from the glass. Opposite him on the other side of the barrier was a guy in an orange jumpsuit. He was tall and solidly built. He had long black hair and a greying beard. His pose mirrored his lawyer’s. Elbows on the counter, face a foot from the glass.

Conspiratorial.

‘Now listen,’ Peterson said.

The lawyer said something in a whisper. Reacher couldn’t hear it.

‘Where’s the mike?’ he asked.

‘In the light with the camera.’ Peterson stabbed a key and the computer beeped the volume all the way up. Then he dragged a red dot backwards a fraction and the segment played again. Reacher craned closer. The audio quality was very poor, but this time the lawyer’s sentence was at least intelligible.

The lawyer had said, ‘You know, the ancient Greeks tell us that a six-hour wait solves all our problems.’

Peterson paused the replay. ‘Ancient Greeks, right? Like ancient Greek philosophers? You said Plato was an ancient Greek philosopher. It’s a code. It’s a message.’

Reacher nodded. ‘When was this?’

‘Two o’clock this afternoon. So a six-hour wait would take us to eight o’clock. It’s six o’clock now. Which gives them two more hours. They’ve already wasted two-thirds of their time.’

Reacher stared at the screen.

‘Play it again,’ he said.

Peterson dragged the red dot back. Hit play. The lawyer’s head, moving forward an inch. The scratchy, whispery sound. The ancient Greeks tell us that a six-hour wait solves all our problems.

Reacher said, ‘I don’t hear it that way. He’s not saying we have a six-hour period during which at some random point all our problems might be solved. I think he’s saying that six hours from then something specific is going to happen in order to solve them.’

‘You think?’

‘Just my opinion.’

‘What kind of thing will happen?’

‘The siren will sound. It’s their only way to get at Mrs Salter.’

‘How can a lawyer make the siren sound?’

‘He can’t. But maybe they can together.’

‘How?’

‘What happens up there at eight o’clock? Are they eating? Feeding time at the zoo is always a good time for a riot.’

‘They eat earlier.’

‘TV time? An argument about CBS or NBC?’

‘You said another riot won’t happen.’

‘Something is going to happen. That lawyer is talking about a future event with a fairly high degree of confidence.’