Robin pretends to be Rochelle and asks for the time of her appointment. After being told it’s Thursday morning at ten thirty, she tells Strike about the appointment the next morning. He then has nearly an hour to get from Denmark Street to the outpatient clinic at St. Thomas’s .

“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 checks that the automatic doors on Grantley Road is the only entrance. Then positions himself twenty yards away and starts to watch the entrance for Rochelle.

Because she enters the building at the Redbourne Street entrance,  Strike doesn’t know if she went to her appointment. He nonetheless finds Rochelle when she leaves his side of the building.

Redbourne Street and Grantley Road don’t exist near St. Thomas’ in real life, nor does a nearby McDonald’s where Strike goes with Rochelle. Like Kentigern Gardens and Vashti, it seems J.K. Rowling made up these locations to suit the story.

You can find St. Thomas’ Hospital on the map below.