Spanner is a techie who helps Strike conduct forensics on Lula Landry’s laptop. He is described as a “pallid, straggly-haired young man” wearing “jeans, a psychedelic T-shirt, Converse sneakers, and a leather bag slung diagonally across his chest.” He has “a first-class degree in computer science” and treats technology with more interest than he does people.
Spanner calls Cormoran Strike by the nickname “Federico,” or “Fed” for short. They share history: Although Strike is ten years older than Spanner, the younger man knows Strike’s friends Nick and Ilsa — or Spanner could possibly be the younger brother of one of them.
In The Cuckoo’s Calling, Strike and Spanner meet in a restaurant in London’s Chinatown called Wong Kei; here, while dining together, Strike gives Spanner Lula’s laptop. Spanner has a lager and a Wonton soup. When Spanner comes to Strike’s office later in the book, he flirts with Robin Ellacott and Strike warns him off of his engaged assistant.