Pool hustler William Fairwick is found at home, fatally stabbed with a broken cue, which seems to fit threats from at least one victim. It turns out he actually saved young tycoon Tom Talmadge, who was beaten in hospital but refused to file a complaint because his suspect is an invisible man, he only explanation which fits the security camera footage of Fairwick's own murder. Castle and Becket are themselves attacked by an invisible enemy, yet try resuming their sex-life and link the case to a top-secret government facility, where Will actually was key researcher.
—KGF Vissers