Strike is in Lismore Circus outside the flat of Wally Cardew when Wally and his fellow YouTuber, MJ, leave Wally’s flat and head toward the Tube. Strike follows and notices someone else following Wally and MJ — a tall man with a very short haircut, a bushy beard and a large skull tattoo on the back of his head. All four men board the Tube, probably taking the Northern Line from Belsize Park, and then exit at Embankment (The Ink Black Heart, Chapter 41).

Wally and MJ make their way to Whitehall Gardens, just a minute’s walk from the Tube station.

Whitehall Gardens is one of the four parts of Victoria Embankment Gardens, which lie along the banks of the Thames. It was originally laid out in 1875 and has a wide array of shrubbery, bedding displays and mature trees. The building facing the gardens was built in 1884, and since 1971 it has housed the Royal Horseguards Hotel.

Strike observes Wally and MJ interviewing and filming passersby, and he keeps an eye on the tattooed man, whom he has now nicknamed “Thurisaz” after his rune tattoo. Strike uses this statue of Henry Bartle Frere as cover.

Henry Bartle Frere was a Welsh British colonial administrator who had a successful career in India, rising to become governor of Bombay. He was later appointed high commissioner for Southern Africa, with less success.

Wally and MJ eventually conclude their filming, and Wally and Thurisaz head out of the park, back toward Villiers Street.

You can find Whitehall Gardens on the map below: