Boyden meets up with an old acquaintance, ex-fighter Billy Briggs, who tells him about an illegal fight being organised by Kieron O'Shea, and offers his services as an informant. Boyden visits a gym, where Briggs' story is confirmed, but he also learns that Briggs is also taking part in the fight. Boyden transfers the case to CID, who show an interest and request further information. Briggs admits to Boyden that, despite medical advice, he is taking part in the fight, as he owes O'Shea money. Boyden goes undercover in attempt to catch O'Shea, but his cover is quickly blown and O'Shea is arrested. Briggs, however, is frightened into withdrawing his allegation, and the case looks on the verge of collapse. (thetvdb.com)