We initially meet DI George Layborn towards the end of Lethal White when he speaks with Strike and Robin at Scotland Yard.¹ Strike remembered that Layborn had “a fondness for colorfully obscene turns of phrase” during their initial meeting and was pleasantly surprised to hear from him in Troubled Blood.²  

Strike and Layborn meet at the Feathers pub where Strike learns that Layborn’s father worked the Bamborough case under Bill Talbot. Layborn provides a glimpse into Talbot’s mental state and expresses a real desire to see this case solved.³

Strike is extremely grateful when Layborn manages to get them the Bamborough file and says to Strike, “‘Buy me a pint and mention me to the press if you ever find out who did it. ‘Valuable assistance.’ ‘Couldn’t have done it without him.’ We can decide the wording after. Might remind this lot I deserve promotion.’” ⁴

^{1: Lethal White, Chapter 68
2, 3: Troubled Blood, Chapter 8
4: Troubled Blood, Chapter 11}