Played by Ioan Gruffudd
A doctor who was shot and thrown off a ship two hundred years ago for refusing to allow a healthy slave to be killed on suspicion of cholera. This event somehow managed to grant him immortality; every time he "dies," he is reborn in the nearest large body of water moments later.
- Actual Pacifist: Doesn't kill or fight, even in self defense. When he does kill - not even in self-defense, but simply to protect Abe - in 1x11, he believes he's fighting Adam, who can't die. Henry is horrified to find the man he's killed doesn't vanish and is merely dead.
- Arbitrary Skepticism: For a guy who has not only lived for 200 years, but whose body completely vanishes and reappears naked in another location when he dies, he's not very open to any other explanation than scientific ones.Henry: I believe that 99.9% of everything can be explained scientificly. There's no fate. No magic. No curses, except for one: my own.
- Big Secret: Given his immortality, the show's main suspense tactic is that he can't let himself die in front of witnesses who will then see his body disappear, which has happened a few times before with nasty consequences.
- Blessed with Suck / Immortality Hurts: Henry will die like anyone else when he takes lethal damage, complete with all the painful consequences. The difference is that his body vanishes to restore in the nearest body of water, making him immortal. He knows a lot of different ways to die, and which ones are worse than others.
- Chronic Hero Syndrome: He can't help himself. On top of taking his responsibilities as a doctor extremely seriously, he has to help others (see My Greatest Failure, below, for how he reacts when he can't). It's led to his being killed more than once.
- Complete Immortality: Since Adam's theory turned out to be wrong, nothing can kill him permanently.
- Creepy Good: His eccentricities and behavior accumulated over his lifespan make him this to modern people.
- The Dandy: As pointed out by Jo.
- Death Seeker: He is at the point where he wishes that one of these times death would just stick, and has been trying to find a way to take away his immortality or die permanently. (Though he admits he doesn't so much want to die as grow old like everyone else.)
- Defrosting Ice King: Henry strictly avoids building relationships, presumably out of the fear of loving them and inevitably losing them to outliving them (Or having to run away to keep his secret). But working with Martinez is getting him to care about people despite himself.
- Everyone Has Standards: Although he ignores a lot of social niceties himself, he's appalled when he realizes Abe wanted him to serve as wingman, so Abe could pick up an old friend's widow. At that friend's funeral.
- Expansion Pack Past: Thanks to his immortality, Henry's knowledge and experience far exceed that of someone his physical age. It is inevitable that he'll bring up an anecdote about something he did that is somehow connected to the case of the week. Other characters, with the exception of Abenote , question why they're surprised when Henry reveals something new and unusual about himself.
- Fearless Fool: Played with. Henry is not precisely afraid to die, but he is willing to undertake life-threatening risk (such as dangling off the 59th Stret Bridge) without too much concern because he knows he'll come back.
- Taken Up to Eleven after he's tricked into killing someone for the first time, as he even stops caring about whether there are witnesses to his disappearance.
- Gentleman and a Scholar: While he tends to avoid interaction with many people, he is always very pleasant and courteous with those he does.
- Hates Small Talk: He's not really fond of interacting and talking with more than a select few people, as pretty much all talk is small talk to an immortal who is well aware of the temporal nature of everything around him.
- Heroic BSoD: He had a year-long breakdown after Abigail left him and had collected a sizable Room Full of Crazy while trying to track her down. It took Abe coming back and clearing it all away before Henry could start functioning again.
- Heroic Neutral: Tries to stay as neutral as possible, preferring to be left alone and out of any sort of trouble, but has a bit of a soft spot for a person in trouble and with a little coaxing will intervene.
- Idiot Ball: What, being around for more than two hundred years hasn't afforded you enough time to pick up some self-defense and fighting skills? Ridiculous. Of course, as he can't actually die, he probably doesn't see any need for them, especially since he is an Actual Pacifist and sees temporary death an acceptable consequence of never taking life.
- Misunderstood Loner with a Heart of Gold: This in the pilot. Due to him being a little odd, a loner, and obsessed with death, Jo initially thought him a suspect until she came to believe in his heart of gold.
- My Greatest Failure: He was a doctor for a while, but stopped in the '50s after he was forced to abandon a dying man so his secret wouldn't be discovered.
- He tried to free the slaves on the ship he was killed aboard but was shot before he could give the key to the shackles and cells to one of the slaves. He carried the guilt of that failure for 200 years until he discovered that the key had fallen from his dead hand and within reach of a slave, leading to a successful uprising.
- Naked on Revival: Every time he dies and comes back to life.
- Nice to the Waiter: In the past, his refusal to let the ship captain kill the sick black slave is what causes his first death.
- No Body Left Behind: As soon as Henry dies, his body and anything he's wearing vanishes.
- Omnidisciplinary Scientist: Thanks to his sheer breadth of experience, Henry is a talented forensic scientist on top of being a medical doctor and pathologist.
- Papa Wolf: The mere thought of Abe being in trouble is enough to get Henry riled up. Abe actually being in danger will drive Henry to kill.
- Parental Substitute: To Abe, whom Henry adopted when he was just a baby.
- Perma-Stubble: Present-day Henry has stubble that varies in thickness but is never completely gone. He's clean-shaven in flashbacks, however.
- Really 700 Years Old: Close though, he's two hundred years old.
- Resurrective Immortality: Whenever he dies, he vanishes and ends up in the nearest body of water. Naked.
- Scarf Of Asskicking: His Iconic Item, which gets Lampshaded a few times
- Sharp-Dressed Man: Almost always dressed in a sharp suit, as he's The Dandy. Fits with his old-fashioned image.
- Sherlock Homage: He's British and is able to deduce facts merely by a quick look at things.
- Supernaturally Young Parent: He now looks half the age of his adopted son Abe (which is near exact in real life, with Gruffudd being 40 to Hirsch's 79).
- The Wonka: He's picked up an irrepressible irreverence for everything sometime in the past two hundred years. Adam insists that it won't last.
- Thou Shalt Not Kill: In two hundred years he has killed only once in self-defense, and is disgusted to learn of Adam's cavalier attitude towards life.
- Who Wants to Live Forever?: Henry certainly doesn't.
Played by Alana de la Garza
A recent widow and a cop who finds Henry to be shockingly useful.
- The Alcoholic: As pointed out by Henry.
- Berserk Button: Played for laughs. She threatens Morgan after he marvels at the perfect symmetry of her face one too many times.
- Cloudcuckoolander's Minder: He may not really be a Cloudcuckoolander, but she is frequently having to explain Henry and his actions to others, or remind him when he's being strange or unintelligible
- Fair Cop: Also pointed out by Henry. She implies that she actually considers being good-looking a detriment to her career; people don't take her seriously as a detective because she's hot.
Played by Joel David Moore
Morgan's coworker in the morgue, who thinks Henry is very weird, but nevertheless repeatedly tries to bond with him despite Henry's stated disinterest.
- Adoring the Pests: Finds rats cute.
- Butt-Monkey: A lot of humor comes from Henry's irritation with him.
- Cuteness Proximity: When he catches a bunch of rats as part of a murder investigation, he grows quickly attached to them. Even giving one life-saving surgery.
- Insistent Terminology: They're graphic novels, not comic books!
- Motor Mouth: He tends to ramble.
- Nightmare Fetishist: Wishes to get an interesting dead body, and reads a graphic novel series about a demon who inspires history's most infamous serial killers.
- No Social Skills: His foot is almost constantly in his mouth.
Played by Judd Hirsch
Abe was found at Auschwitz by Abigail and Henry and was subsequently adopted by them. He's aged normally while Henry's appearance stayed the same so the son now looks twice as old as the father. Abe now addresses Henry by name to maintain the illusion that Henry is the son of a deceased friend of Abe's.
He was a paratrooper in Vietnam and a social activist afterwards. He now runs an antique store.
- Cool Old Guy: In part because he knows Henry is immortal, Abe envies him his permanent youth, and tries to live his own life as enthusiastically as possible, up to and including trying a half-pipe at 65 years old.
- Happily Adopted: While Abe expresses an interest in discovering his roots he considers Henry and Abigail to be his true parents. It's later revealed that Abe and Henry are related through an illegitimate child of Henry's uncle.
- My Greatest Failure: During the Vietnam War, he froze during an ambush and three of his squadmates were killed. He's wondered every day since if he could have saved them.
- The Rival: The Berkowitz brothers, who are also antiquers, are bitter rivals with Abe, and he returns the sentiment.
- Secret Keeper: To Henry.
- Supreme Chef: Episode 2 has him using Henry as a guinea pig for his cooking in preparation for a date, and then mentions him cooking rather exquisite foods during the date itself.
Played by MacKenzie Mauzy and Janet Zarish
Henry's wife as of the 1940s, who eventually left him. She'd be in her nineties if she's still alive.
- Doppelgänger Replacement Love Interest: The women Henry finds himself drawn to all bear an uncanny resemblance to Abigail.
- Secret Keeper: While they were married; if Abigail is still alive she'd be in her 90s. Morgan's continued occupation as a medical examiner is indication that if she still lives, she still keeps the secret. Otherwise, she took it to her grave. Eventually we find out she did just this, even taking her own life to prevent Adam from finding Henry.
- Temporary Love Interest: She declared she wouldn't let Henry end their relationship due to his Big Secret. She became his wife, but eventually left him in 1985.
Played by Lorraine Toussaint
The precinct's detective commander. She's frequently frustrated by Henry's antics.
- Affectionate Nickname: Her subordinates occasionally address her as "Lou", a contraction of her rank and title.
- Deadpan Snarker: She reacts to strange developments with an understated dignity that makes her comments all the more funny.
- It Gets Easier: Has this opinion about cops forced to shoot suspects.
- Reasonable Authority Figure: When Henry reveals that he has a stalker in "Skinny Dipper" who is trying to frame him for murder, she not only believes him, she takes immediate action to not only find the killer, but to protect Henry from the stalker.
- Sassy Black Woman: Downplayed Trope, she's snarky but not unjustified.
- Shipper on Deck: She seems to want her subordinates to be happy and have fulfilling personal lives; she's almost always the first one to suggest one of her subordinates go on a date with someone they like.
- Verbal Backspace: After Henry got arrested for buying heroin to see if he could trace it to the one that killed the victim.Reece: That's the dumbest police work I have ever seen.
Lucas: [coming in] Okay, I couldn't find the rat that ate the victim's face, so I just got the whole nest.
Reece: Second dumbest.
Played by Donnie Keshawarz
A detective in the police department.
- Acrofatic: Despite his size, he's more than capable of keeping up with a fit crook.
- Big Fun: He's noticeably chubby.
- Butt-Monkey: He gets this, but not as much as Lucas.
- Hidden Depths: He used to be in a band and played at The Trash Club which, in the show's universe, is held in the same esteem as CBGBs.
- The Watson: A secondary one for Henry.
Played by: Burn Gorman
Another immortal who discovers Henry, with a sinister purpose in mind.
- And I Must Scream: The Season 1 finale: Henry realizes that killing Adam with the puggio might not actually result in Adam's permanent death so he injects air into Adam's brainstem, causing a pulmonary embolism resulting in Locked-In Syndrome. Adam's brain is fully functioning but he can't move, speak, or communicate in any meaningful manner.
- Being Tortured Makes You Evil: Like Henry, his secret has led to imprisonment and torture. Unlike Henry, he didn't maintain a very positive outlook on the world.
- Big Bad: Shaping up to be this towards Henry.
- Bond Villain Stupidity: Oh Adam, if you hadn't decided to gloat over Henry's body...
- Even Evil Has Standards: He really hates Nazis, as you might expect from someone who had received the treatment that he did at their hands.
- The Faceless: Mostly heard on the phone, with a brief glimpse of his hand. Until he's revealed in "Skinny Dipper".
- Hidden Agenda Villain: He says he's just bored and it's interesting to have found another like him; but it's anyone's guess what he actually wants with Henry now that he's found him.
- I Have Many Names: He's used quite a few over his life, with "Adam" simply being his own suggestion for what Henry should call him. He also uses the identity of "Lewis Farber", psychiatrist.
- Immortality Immorality: Has been around so long, he feels he's now Above Good and Evil.
- Jack the Ripper: He's strongly implied to have been the Ripper, or at least a copycat.
- Monster Sob Story: Adam was a prisoner at Auschwitz, and when the Nazis discovered his immortality, he was painfully vivisected and experimented on by Josef Mengele. That said, it's not Adam's Freudian Excuse for being a sociopath, but it is the reason he says he won't harm Abe, another Auschwitz survivor.
- Must Make Amends: In his own way he seems to have steered into this territory after tricking Henry into killing a man.
- My Greatest Failure: He seems to see letting Abigail die as this, as he is apologetic to Henry and even did revive her only for her to slit her own throat.
- Not So Different: Or so he claims. He tells Henry that he was once very much like him - decent and compassionate - but two thousand years of endless life has dulled his empathy toward mortals (Being experimented on by frigging Josef Mengele probably didn't help much either). Like Henry, it was a moment of compassion - stepping in to try and stop the Assassination of Julius Caesar - that caused his first death, triggered his Immortality, and led him to where he now...and one some level he resents his own compassion for that reason. At one point he taunts Henry with the promise that one day Henry will end up just like him: bitter, amoral, and detached from the world at large.
- The Older Immortal/Really 700 Years Old: Claims to be over two thousand years old when talking to Henry.
- Red Herring:
- It repeatedly looks like he's behind some of Henry's weirder cases, when actually he's just following him. The Pilot is an especially notable example; it appears to the audience (and Henry) that he caused the train crash and is investigating the sole "survivor," but in reality he just stumbled upon it by blind luck and realized that Henry was immortal.
- Villainous Rescue: A very dark version. Henry is very rapidly bleeding to death in a basement, but Martinez is in the building. He can't possibly fake his way out of surviving the punctured lung and vena cava or the broken back that a killer's inflicted on him. Then Adam comes in through the street door to... help.Adam: Your partner's bound to find you, and you die in front of her... that's no good for anybody. You can thank me later. [slits Henry's throat]
- What Happened to the Mouse?: It was mentioned he has a wife, but aside from Henry pointing that fact out she is never seen or brought up again.
- It's possible he lied and just bought or stole the picture of the woman in order to flesh out the lie. I could be wrong, but I don't think he was actually in the picture with her. Even if he was, she could have just been a friend/acquaintance.
- Who Wants to Live Forever?: Two thousand years of interminable life has not had a universally positive effect on Adam's mentality.