America's first African American heavyweight boxing champion, Jack Johnson, has a chance encounter with a mysterious Irishman, named Altamont, when they meet at the boxer's restaurant, Cafe de Champion, in August 1912. Johnson's new relationship with the unusual man, with beady eyes and hawk-like nose, places him in an unusual circumstance to help Altamont get out of a tough situation. In 1913, Johnson is nailed with a felony conviction in the American court system and flees to Canada, and later travels to England, to meet with fight promoters. But a stolen South African 'blood diamond' and a grudge harbored against the controversial boxer from the past, puts Johnson's life in peril while on British soil, reuniting him with the mysterious Altamont. Will Johnson uncover the true identity of this Irishman, and entrust his life to Altamont's care? And as the action unfurls, Johnson forms an alliance with a black British rogue and grifter, Steve Dixie, but can this man be trusted?
With all the uncertainty Johnson faces in a foreign land, and for his own protection, he calls in a favor from his American Mafia cronies, finding himself in league with American teenage mobsters, Alphonse Capone and Frankie Yale. Johnson, Altamont and their entourage of companions' race against the clock, not just to save Johnson's life, but to preserve the national security and future of Britain as well.