The Spanish Game by Charles Cumming

The provided excerpts appear to be from a spy novel, likely "The Spanish Game" by Charles Cumming, judging by the introductory review snippets and author information. The text follows several interconnected narratives: first, a Russian character carrying out an assassination in London, driven by a deep need for vengeance; second, the complicated family dynamic and strained relationships between Ben Keen, his wife Alice, and his brother Mark, particularly concerning their estranged father, Christopher Keen; and third, the world of British intelligence, focusing on the efforts of MI5 agent Stephen Taploe and others to investigate the possible involvement of Mark's employer, Sebastian Roth’s Libra company, in organized crime connected to the Russian mafia and the deceased father, Christopher Keen. This investigation, which Mark secretly aids, is complicated by the murder of Christopher Keen and later, the murder of a former CIA contact, suggesting a dangerous conspiracy tied to the father's past SIS activities in Afghanistan and the actions of a former KGB agent. Ultimately, the intelligence services make a morally dubious deal with the mafia to apprehend the killer, Dimitri Kostov, who is then betrayed and presumably executed by his former associates.