Tim Ashcroft is described as a “tall, prematurely balding young man” (Ch 21) who used to have a full head of red hair. (Ch 24)

We first see Tim Ashcroft as the man behind the camera filming Edie Ledwell and Josh Blay for their YouTube video.  Josh introduces Tim as the man who voices  The Worm in The Ink Black Heart cartoon. (Ch 14) 

When Strike and Robin first meet with their clients at The Arts Club, Allan Yeoman puts forward Ashcroft’s name as someone they should talk to, saying that he can’t have liked being dropped from the cartoon as he had acting ambitions.  (Ch 18)

Strike first sets eyes on Ashcroft after following Seb Montgomery to Highgate.  Seb meets with Tim outside Highgate Tube Station and they go on to meet with Nils de Jong and Wally Cardew in the Red Lion and Sun. (Ch 21)  Later, in his notes to Robin about this surveillance, Strike includes the fact that Tim Ashcroft is currently a member of a theatrical company, called the Roving School Players, that performs in schools. (Ch 24)

When Robin and Strike speak with Flavia Upcott outside her house, Robin asks Flavia if she has seen The Ink Black Heart.  Flavia says she quite likes it and that The Worm is the funniest. She tells them that Tim is nice and that he showed her how to draw animals by starting with shapes.  (Ch 34)  The fact that he can draw keeps Tim in the running as a potential Anomie.  

Robin uses her Venetia Hall disguise to interview Ashcroft, after luring him in using a fake website called “Arts and Drama in Schools”.  They arrange to meet in a bar called Qube in Colchester, where Tim is living with his parents.  Robin asks Tim many questions about his work with the touring theatre company, and about his ‘recent starring role at his his local theatre’, before asking questions about his involvement with the cartoon and his thoughts on Anomie. (Ch 45)

Later in the book it becomes clear that Ashcroft is a very unsavoury character indeed, and is using his various Twitter accounts for nefarious purposes.  Strike takes advantage of a chance meeting with him to give him a piece of his mind.