Ophelia Price is one of the four Chosen who acts as Caleb's love interest. Whether or not she loves him back is controversial throughout the series and is up for debate. She acted as Caleb's original gateway into the Cabal, after the death of her husband and son (at the hands of the Cabal, though Ophelia does not blame the cult for this but rather her husband).
Blood II reveals more about her personality, that she is a cold, cunning, manipulative, woman and prefers stealth to strength. She uses the Tesla Cannon and Sniper Rifle primarily. She and Caleb's relationship is tenuous, mostly consisting of back-and-forth jabs with no real affection ever being shown; though under the surface of this is left ambiguous. In Blood she is shown in brown pants and shirt with a green cape and has short flowing red hair. In Blood II she wears a leather jacket and pants and now has shorter red hair styled into spikes.
She is voiced by Lani Minella in Blood II: The Chosen (who also voiced Gabriella). She has a few vocals in the first cut scene of Blood, but is not identified in the cast, though she may be voiced by "Celeste". When left alone Ophelia will recite random verses from The Dole of the King's Daughter: Breton by Oscar Wilde and The Truth the Dead Know by Anne Sexton to herself.
 Early Years
Ophelia's entrance into the Cabal came during her college years when a genius student created a reanimation serum. The Cabal sent zombies into the campus to take him and the serum. As zombies apparently want to do, they wandered to the "largest collection of defenseless and scantily clad women" - Ophelia's sorority house. Observing the power that the Cabal wielded, Ophelia had an evil inspiration: ditch her education, family and associates and join the cult. After destroying all incriminating evidence against her (as she knew they would not take some "silly sorority girl") she presented herself to the cult.
 The Cabal
Caleb found Ophelia in the remains of her homestead, during his criminal wanderings. He was struck by her beauty but also the words in her insane ramblings. As he rehabilitated her, Caleb learned about the Cabal and their master Tchernobog and joined as well seeking power. It is implied that he and Ophelia became lovers. Eventually, the two rose through the ranks and, along with Ishmael and Gabriel, became members of the Chosen; Tchernobog's elite generals.
 Betrayal and Death1871 and 1928, Tchernobog summoned the four Chosen to the Hall of the Epiphany, Tchernobog's chamber. Instead of giving orders, as the Chosen thought, Tchernobog told them that they had failed him and that he disavowed them all. The four were stunned as Tchernobog sent his lieutenants to take the Chosen one by one. Cheogh swooped down from the darkness and kidnapped Ophelia, causing Caleb to jump to her aid but fail. Cheogh took her to the Altar of Stone where he crucified her on a stone tablet. After Caleb was resurrected and defeated Cheogh, he cremated her body on the altar.
At some point in the year 2028, Ophelia is resurrected by unknown means although Ishmael says that "she was the first to come through". It is likely however that the tears in between the realities had something to do with her and the others Chosen's return to the land of the living. She is held by the Cabal in the Temple of Poon in CabalCo headquarters. Once Caleb arrives and finds Ophelia tied to the altar, she attempts to seduce Caleb into assisting her, before Gideon arrives and spirits her away through another rift.
After Caleb catches up with Gideon, Ophelia appears on the rooftop, inexplicably free, and calls Caleb a "dumb bastard" for following Gideon in. They eventually reunite in Reality Beta after the defeat of The Ancient One.
 The Nightmare Levels
During their journey back home, the four Chosen stop at a campfire and tell ghost stories. Ophelia, nonplussed by Caleb's disappearance, tells of her time in Iota Eta Pi during the Cabal attack.
 Relationship with CalebBlood readme file. In fact, the Blood II instruction manual describes her as "resurrected into a world with no future and full of disgust over the undead creature that she has become, Ophelia is desperately searching for a way out. She'll do whatever it takes to escape from a world gone mad, a body she no longer knows, and the love of a man she's grown to despise" and other background material hints that one of Caleb's motivations in Blood II is to win Ophelia back, though this never really appears in the game.
She does share the other Chosen's frustration over Caleb's stubbornness about accepting that he needs to seal the rifts, but this does not equal hatred, and is annoyed when he follows Gideon through the rifts. However, once it is all over her annoyances with him are mooted, though what remains is unclear. She doesn't seem to mind being trapped with him in the other world. In The Nightmare Levels, during her story she says, "Don't tell Caleb though, he would never forgive me", and when meeting him at the end, says "Umm.. you are having a bad dream... Caleb, dear" hinting at some secret affections, or at very least a fear of Caleb turning against her.
Likely, their relationship is based on a tenuous bond of the hardships they went through - Ophelia's insanity, her involvement with the Cabal and subsequent condemnation, and being resurrected 100 years later. It is known that the two were lovers back when they where serving Tchernobog, however it is unknown how this has survived through death, time and battle.