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?

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's mysterious anonymous caller confronts him by framing him for a murder. With the police closing in he is faced with the prospect of having to either leave town or confess his true nature to everyone.

A murder opens the door to a hoard of Nazi secrets and the return of an old enemy.

When the owner of a treasure hunting salvage company is murdered, the investigation leads Henry and Jo on a chase to find the missing ship’s gold and the killer.

When a human heart is delivered fresh out of a body to the homicide division, Henry and Jo end up in the middle of a Jack the Ripper copycat murder investigation. But it doesn't stop there. A second killing resembles another infamous, unsolved crime: the Black Dahlia murder. Henry has seen it all before, as flashbacks show his involvement with the two original cases from two very different periods of his long life. However, Henry's anonymous caller tips him to search beyond the clues of these classic killings and leads the police squad to profile a very different, yet... He's a 200 year-old detective. You have to know there'd be a Jack the Ripper episode.

A human foot in a blood-soaked ballet slipper is found in a bin at a theater.

Henry and Jo investigate the murder of an exiled king; Abe discovers something about his bloodline.

A deadly subway collision is investigated as a New York City medical examiner attempts to discover the truth behind his inexplicable immortality.

The death of Gloria Carlyle, the elegant, seemingly ruthless matriarch of one of New York's wealthiest and oldest families, brings a world of hurt down on her family. After Gloria is found dead at a Metropolitan Museum of Art gala celebration of her philanthropy, Henry runs through a variety of suspects and motives but is pulled from the case when the family demands faster answers. Abe assists Henry and Jo entering the family's estate sale for important clues through his antique connections. Meanwhile, Henry is tormented by the haunting and melancholy memories that ...

Henry and Jo become immersed in the world of a dominatrix, who doesn't dole out pain for kinky pleasures but for therapeutic purposes. Meanwhile, Abe reacquaints himself with his own form of pain and pleasure - his former wife.

Jo and Henry pursue the killer of a jewelry store burglar who has a connection with Jo's dead husband.

A college student obsessed with the 1970s is murdered. Sparks fly between Henry and a professor.

Henry's secret is jeopardized when he investigates the death of an underground activist.

While Jo and Isaac are at a punk rock club, a mummified body is found in the wall.

When all the ingredients for a sensational, scandalous murder investigation are combined -- a fairytale romance gone wrong, a jealous mentor and lover, an anxious, wealthy father of the beautiful fiancée - does love really conquer all? An engaged British aristocrat turns up dead in Central Park, and his identity is called into question, as well as who killed him. The trail leads Henry and Jo through one of New York's top luxury department stores and from working class to upper crust New York society. Henry remembers back to 1957 when, once again, he and his family had...

Henry returns to work to investigate the murder of a young investor, who happens to be the son of one of Abe's wartime Army buddies. Abe and his Army buddies decide to play detective and solve the case.

After Henry pegs the case of a would-be bridge jumper as a homicide while the police label it a suicide, he and Jo go on a rogue investigation for proof. Meanwhile, Henry's anonymous caller surfaces again. Apparently, he has been tracking him for years. A letter on antique stationery might provide Henry a fascinating clue about the caller, and he enlists Abe's help in tracing the note's history to a foreign locale. Revealing flashbacks unveil the beginning of Henry's great love affair with his soon-to-be wife, Abigail.

A man dies when his car catches fires and incinerates him. The various suspects center around the world of jazz and concerns the true author of one of its greatest standards.

Henry is interested in aging and how to die, but New York's wealthy elderly are chasing a way to turn back the clock. A clinic is dispensing a pricey product - Aterna - which is supposed to provide the much sought after fountain of youth. But instead, Henry and Jo are confronted with multiple deaths from the costly potion, which instead of revolutionizing the aging process, is turning people's brains into swiss cheese. Meanwhile Henry remembers back to dear friend who was diagnosed with tuberculosis in 1906 and discovers a link to this current case. Unbeknownst to ...

Dr. Tyler Forester, founder of a free medical clinic and the son of a Wall Street billionaire, is awarded one of the city's highest honors for his humanitarian efforts. A few hours later, he is found dead in his tiny apartment. Henry and Jo discover that Tyler's life of privilege and those of his thick-as-thieves Hamilton School classmates took a fateful turn one night many years ago. Now, the nightmare they thought they buried deep within themselves has come back to haunt them. Meanwhile, Henry recalls being faced with the terrible dilemma of being forced to decide ...

What looks like a drug overdose death of a reformed junkie-turned community activist results in Henry and Jo tracking a murderer. The complex investigation involves dirty dealings between a real estate developer and a community organizer with millions of dollars at stake. Henry flashes back to the same 1890s New York tenement where he worked as a doctor to help the poor, including an orphan boy who gives him a special handmade gift. Meanwhile, Abe cooks up a Sunday dinner feast for Henry, Jo and himself. When Jo tries to find out how the two men know one another, ...