Madeline is Strike’s girlfriend for much of The Ink Black Heart. She is a successful jeweller with her flagship store on Bond Street. She lends and sells jewellery to high-profile clients, including royals and A-list actors. One of her clients, Strike learns, is the pop singer Gigi Cazenove, who was found hanged on the morning of New Year’s Eve, the day Madeleine and Strike first met. Her other clients include Lucinda Richardson (another famous person who Madeline’s “OTT” security guard stopped at the door) and Charlotte Campbell, who had agreed to model for her the previous year. Strike likes that Madeline is entirely self-made and likes her commitment and passion for what she does.

She is described as having red-blonde hair, hazel eyes, and looking like Robin Ellacott. Strike notices when he puts his arms around her waist that she’s thinner than Robin.

She lives in Eccleston Square in Pimlico with her sixteen-year-old son, Henry, who she’d given birth to at nineteen. Henry’s father had, like Madeline, been nineteen when he was born and had gone on to be a successful interior designer. Strike is surprised by how amicable his and Madeline’s relationship seems to be. After leaving Henry’s father, Madeline then married an actor called Jim. They divorced when he left her for the leading lady in his first-ever film. Madeline tells Strike that Jim totally screwed Henry up and betrayed his trust.

Jim’s adultery means she is particularly insecure in her relationship with Strike, and wrongly suspects that Strike and Robin were once a couple after Charlotte tells her so. Strike is furious at Charlotte and tells Madeline that she shouldn’t believe a word of what Charlotte says.

Strike first meets Madeline on New Year’s Eve 2014 in Annabel’s, a members-only club on Berkeley Square. In the club, Charlotte Ross’ stepbrother Valentine Longcaster tells Strike that Madeline thinks he’s sexy. Shortly after, Madeline approaches Strike and they start chatting. They kiss at midnight and then Madeline puts her phone number into Strike’s phone before disappearing into the crowd.

In chapter 8, Strike meets Madeline for their sixth date in Nightjar, a speakeasy cocktail bar hidden away on City Road. Madeline has the Orca Punch, Strike a Toronto. Their previous dates had also involved Madeline picking out the restaurants or bars to meet and ending at her home in Pimlico. Wanting larger portions of food than what these bars provide him, Strike takes the precaution of having a Big Mac before meeting Madeline on dates.

Strike never tells Madeline about the cases he is working on, which leads to the running joke that he is investigating the Mayor of London, Boris Johnson. “Nicking hub caps, mugging old ladies –- the usual.”

Robin only finds out about Strike dating Madeline when Charlotte arrives at the office and tells her that she looks like her. Up to then, Strike had been keeping his relationship with Madeline secret. In Bob Bob Ricard, Robin tells Ilsa about Madeline, who then Googles her and also notices that she looks a lot like Robin.

In chapter 51, Madeline hosts a launch party at her flagship store for a new jewellery collection. Strike arrives shortly before it ends and hides in an doorway where he also sees Henry and a friend smoking a spliff. After a brief encounter with Charlotte outside, Strike joins Madeline in her store where they have their first big row, for which Charlotte and too much champagne are partly responsible.

In chapter 59, Strike goes on a date with Madeline to Kazan, a Turkish restaurant near her home. They have particularly enthusiastic sex that night, mostly on Madeline’s part. Strike suspects that she is trying to make up for their row at her launch party.

After finding out Strike stayed at Robin’s flat, Madeline confronts Strike over the phone. Strike calls her back when he is in his hotel room in Whitstable and he ends the relationship.

In chapter 94, a drunk Madeline arrives on Denmark Street to find Strike about to enter the office building. She accuses him of being a liar and that she had been warned about him. She repeatedly punches him and kicks him with her stiletto heels, further damaging his injured and extremely sore stump. Strike tells her to fuck off.