At her request, Strike visits Kelsey Platt’s sister, Hazel Furley, at home.  He takes the tube to West Finchley Station…

… and due to the poor state of his finances walks to Hazel’s house in Summers Lane, which takes him around half an hour. 

‘Sweating slightly in the mild weather, he moved through road after road of quiet detached houses, cursing the place for its leafy quiet and its lack of landmarks’ (Career of Evil, Chapter 34). 

‘Finally, thirty minutes after he had left the station, he found Kelsey Platt’s house, smaller than many of its fellows, with a whitewashed exterior and a wrought-iron gate’ (Career of Evil, Chapter 34). 

Summers Lane is located here: