Rush hour past, the crowds on the Tube had thinned. Strike was pleased, because the end of his stump was still smarting, to find a seat with ease. He had bought himself a pack of Extra Strong Mints at the station kiosk before boarding his train, and was now sucking four simultaneously, trying to conceal the fact that he had not had time to clean his teeth. His toothbrush and toothpaste were hidden inside his kitbag, even though it would have been much more convenient to leave them on the chipped sink in the bathroom. Catching sight of himself again, in the darkened train window, with his heavy stubble and his generally unkempt appearance, he asked himself why, when it was perfectly obvious that Robin knew he slept there, he maintained the fiction that he had some other home.

Strike’s memory and map sense were more than adequate to the task of locating the entrance to the psychiatric unit at St Thomas’s, and he proceeded there without mishap, arriving at shortly after ten. He spent five minutes checking that the automatic double doors were the only entrance on Grantley Road, before positioning himself on a stone wall in the car park, some twenty yards away from the entrance, giving him a clear view of everyone entering and leaving.

Knowing only that the girl he sought was probably homeless, and certainly black, he had thought through his strategy for finding her on the Tube, and concluded that there was really only one option open to him. At twenty past ten, therefore, when he saw a tall, thin black girl walking briskly towards the entrance, he called out (even though she looked too well-groomed, too neatly dressed):

‘Rochelle!’

She glanced up to see who had shouted, but kept walking without any sign that the name had a personal application, and disappeared into the building. Next came a couple, both white; then a group of people of assorted ages and races whom Strike guessed to be hospital workers; but on the mere off-chance he called again:

‘Rochelle!’

Some of them glanced at him, but returned immediately to their conversations. Consoling himself that frequenters of this entrance were probably used to a degree of eccentricity in those they met in its vicinity, Strike lit a cigarette and waited.

Half past ten passed, and no black girl went through the doors. Either she had missed her appointment, or she had used a different entrance. A feather-light breeze tickled the back of his neck as he sat smoking, watching, waiting. The hospital building was enormous, a vast concrete box with rectangular windows; there were surely numerous entrances on every side.