Cardiff’s Tiger Bay has a claim to be one of the oldest multicultural communities in the UK. As coal production boomed in the 19th century, the area became an industrial hub, with people from all over the world putting down roots. This continued into the 1950s, when, as the British-Somali author Nadifa Mohamed writes in her third novel, The Fortune Men, ‘an army of workers’ was ‘pulled in … to replace the thousands of mariners lost in the war: dockers, tallymen, kickers, stevedores, winch men’. But as well as being a place of opportunities, the area was a hotbed of crime, the boats leaving the harbour every day doubling up as getaway vehicles for those who had caused mischief during their stop-offs.

In February 1988, a twenty-year-old woman named Lynette White was killed in Tiger Bay. Three black and mixed-race men were eventually convicted of her murder. They were exonerated fifteen years later and the case has become known as one of the British justice system’s most notorious failures. The Fortune Men is inspired by a similar miscarriage of justice associated with the area: that of a Somali man named Mahmood Mattan, who in 1952 was convicted of the murder of Lily Volpert, a Jewish shop owner.

When we meet him in a milk bar at the start of the novel it is 1952 and 24-year-old Mahmood has not stepped foot on a boat for three years. He’s a loner, hardened by his time at sea, who now gambles, drinks and thieves. He has an estranged wife, Laura, who is white (their marriage has caused consternation in the community, not least to Laura’s grandmother), as well as three children. Lily Volpert is fictionalised here as Violet Volacki. One evening she is found by her sister, Diana, in the family shop with her throat slashed. Police turn up at Mahmood’s rented lodgings, stating that ‘a coloured man is believed responsible’, and although a preliminary search of his room reveals nothing suspicious, a few days later Mahmood is arrested.

Mohamed offers a bleak view of the British justice system at the time. We know from the start that Mahmood is innocent; he is dragged into suspicion not through any hard evidence but because of the racism of the police, who are all too happy to lap up the dubious testimonies given to them by opportunists and enemies of Mahmood. These include his landlord and an elderly lady who testifies against Mahmood at his trial after finding out that the Volackis have offered a handsome reward for anyone who can lead them to the murderer. The Volackis themselves are among the few who think that Mahmood is innocent. Asked to look at a police line-up that includes Mahmood, Diana and her daughter decide that he isn’t the man they saw near the shop at the time of Violet’s murder, much to the annoyance of the police: ‘Detective Powell seemed disappointed in them and led them back out to the street with a request they think hard about what they actually remembered.’

The early part of the novel is narrated in bustling prose that captures the energy of this little patch of Cardiff. Mohamed confidently provides historical context to the story, showing how the state-sponsored oppression experienced by Jews and Somalis alike has a long lineage. Kristallnacht still lives in the Volackis’ memories: Diana recalls waiting for the British government ‘to react to this barbarism’ and being startled when it merely ‘wagged a half-hearted finger at Herr Hitler’. One of the best chapters covers Mahmood’s early life, showcasing Mohamed’s skill for roving, evocative sentences. Born in British Somaliland ‘to a mother well past forty’, she writes, ‘Mahmood had arrived into a world wet and red from the slaughter of emaciated animals, a world of Indian civil servants under shady trees scribbling nomads on to welfare lists, of sacks of government rice and stewed wild plants’. Mohamed chooses to relay the trial, by contrast, in the form of a simple transcript, a beautifully clinical method that lays bare the contradictions between each testimony and the shaky foundations on which Mahmood’s prosecution is built. When the verdict comes, we realise that the trial constituted little more than a formality.

If Mahmood is hard to warm to at first, he keeps this novel alive as it races towards its conclusion. Mohamed seems to lose interest in the surviving Volackis (the bulk of Diana’s trauma is dealt with in a couple of pages, slightly hammily, as we see her complaining to her doctor of insomnia), but I welcomed more time spent with Mahmood. He is drawn with acute sensitivity: his time in prison, waiting for his trial and then multiple appeal hearings, is characterised by a slow evolution from sheer bafflement to defiance (when Laura warns him that murder is ‘a hanging offence’, he replies, ‘It is if you’re guilty, I ain’t got nothing to do with it’). Mahmood’s innocence is also his hamartia: his steadfast faith that ‘the truth kill the lie’ means that he neglects to meet the trial on its own terms, to play the game, and ends up, in the words of his lawyer, denying ‘certain pieces of evidence which are enormously in his favour’. For the real Mahmood Mattan, whose prosecution was declared flawed in 1998, the truth came too late. Nadifa Mohamed has produced a fitting memorial to him.