What appears to be the dead body of an ordinary old man, turns out to be of royal lineage with an unusual connection to Henry. A familiar scar and radioactive poison point Henry and Jo to the man being an assassinated king in exile. Moreover, a half century earlier, Henry remembers performing an emergency, life-saving operation on a boy while on his honeymoon with Abigail. The boy turned out to be a prince of a tiny crumbling kingdom. Life came full circle as the boy grew up to be a king -- and now, the murder victim lying in Henry's morgue. The mystery deepens when other members of this royal family are poisoned and it is revealed that the king has an heir. Meanwhile, Abe continues to investigate his roots and discovers something amazing about his bloodline.
The death of a young college woman sends Henry and Jo back to the cultural hotbed that was New York in the 1970s. Murder victim Sarah Clancy's fascination with authentic 70's attire is more than just a fashion statement, it is revealed that she had an unhealthy obsession with the past. The investigation ironically leads Henry and Jo back to college professor Molly Dawes (aka the dominatrix Iona Payne), who taught Sarah in a course on sexual identity. Molly not only agrees to help in the search for the killer, but she and Henry spark a hot, romantic connection. Flashbacks to 1979 reveal Henry and Abigail's struggle coming to terms with their age difference as they try to celebrate their anniversary with a night on the town.
Henry tackles the most important case of his career: the disappearance of the love of his life, Abigail, after she left him. Desperate to find out where she might have gone, Abe, unbeknownst to Henry, secretly contacts Lucas to help find clues to her whereabouts. Already involved in a murder investigation with Jo, Henry involves Lucas and the team of detectives under the guise of searching for "Abe’s mother" -- never letting on his own relationship with Abigail. Henry and Abe’s anxiety is ratcheted up as one terrifying domino falls after another until Henry uncovers the horrifying details of Abigail's last secret.
Henry and Adam have been on a long, unrelenting collision course, which is about to come to a head – possibly bringing about one man’s death – with only Jo standing in the way. Henry and Jo’s murder investigation into a museum worker’s death centers on a priceless missing ancient dagger, which not only ended the life of Julius Caesar, but also killed Adam the first time. Meanwhile, Adam knows that there is something that Henry fears more than death – that Jo might discover his mystery. The two men tangle in a tumultuous game-changing confrontation. But at long last, will Jo finally learn about Henry’s secret?