(Covers information from Anderson's universe)
Doc was an informant of the Umbrella Corporation, and was sent by his superiors to keep track of survivors in Raccoon City. His knowledge about medicine, as well as his kind and likeable personality, helped him climb up the ranks and become a leader of a large group of survivors holding up in Raccoon City, with his comrades unaware of his duplicitous nature. He is portrayed by Irish actor Eoin Macken.
Doc is a longtime and loyal operative of the Umbrella Corporation, as evidenced by knowing the real Dr. Alexander Isaacs personally. After the global T-virus pandemic, which began in 2002, he is sent by Isaacs and Albert Wesker to keep track of survivors in Raccoon City as part of Umbrella's plan to initiate the epidemic to cleanse the Earth and start anew with the Umbrella employees in charge.
Leading the Raccoon City survivors
He has a charming personality and strong leadership skills, and this, accompanied by his medical expertise, helped him rise among the ranks and become leader of the survivors. This puts him at odds with Christian, who believes that he should be in charge instead, thus leading to infighting and factions within his group. Razor serves as Doc's second-in-command. While he is doing this, he continually gives updates to Wesker to serve Umbrella's ultimate plan.
Eventually, the group discovers a crashed Umbrella helicopter, and they rescue Claire Redfield, who joins the group and eventually begins a relationship with Doc. Claire and Doc eventually become leaders of the group together.
As Alice heads to the Hive to find the antivirus located inside, Doc secretly watches her from their base, as Umbrella wants to capture Alice. Alice spots their base and heads to their direction, where Doc shines a light to Alice to warn her of their trap, which she falls into anyway.
Doc fends off Christian's suggestion to kill her as they might need her for Umbrella's imminent attack. As he is about to inject her with pure adrenaline to wake her, she already wakes up and puts him in a chokehold, forcing the rest of the survivors to hold them at gunpoint. Doc explains to her that he wants her awake because "something's coming", before the situation is defused when Alice recognizes Claire.
Alice recovers in a medical clinic in the building, and Doc offers her a medicine to help her recover; to gain her trust he drinks a sip himself before she finally drinks it. Claire explains to Alice that she and Doc are together, but Alice confides to her that someone in the group is watching her, referring to Doc signalling her earlier.
Fight with Umbrella
The group spots the convoy of Dr. Isaacs' clone leading a horde of Undead to their location. Christian is still distrustful of Alice, leading him to hold her at gunpoint and having a stand-off with Razor, Doc and Cobalt. Doc defuses the situation by stating that just because Christian wants to be a leader, doesn't mean that he should be. Doc assists in fortifying the base, and arms himself with a nailgun.
When Umbrella's forces attack, the survivors manage to repel them, but Isaacs releases a "bait" to run for the base. Doc and Claire attempt to rescue her, but Isaacs kills her last-minute, leaving the base vulnerable to attack, but the survivors manage to repel the attack by Umbrella.
Doc is among the volunteers to go with Alice to venture into the Hive to retrieve the antivirus. As they enter the Hive, Alice is secretly informed by the Red Queen that Umbrella has an informant, and that he or she may be in Alice's group. Doc manages to fend off several traps initiated by Wesker, however the remaining survivors are separated in the process.
After Alice kills a bio-weapon that had killed Razor, Doc manages to find her and asks what the creature was and if she has found the others, to which she says that it was a human bio-weapon, she was also unable to locate Claire and that Razor is dead. The two make their way past the laser room and to the control panel, where Alice gives Doc an unloaded gun, having deduced that he was the traitor, as he was still alive while the others have died. They make their way to the main headquarters, where en route Alice and Doc implant explosives at the cryotubes of the Umbrella employees in stasis.
The two confront Isaacs, where he tells them to drop their weapons or else he prematurely destroys the anti-virus underground. Alice drops her weapon, while Doc points his gun to Alice, revealing his true allegiance to her and Claire, who arrives at gunpoint from Wesker. Doc observes as Alice is told by Isaacs of her true nature as a clone of Alicia Marcus.
"How did you know it was me?"
When Alicia fires Wesker, making the Red Queen crush his legs with a blast door, Doc attempts to fire at Alice, but then realizes that his gun is empty. Alice uses his gun to knock him down. Doc asks how she knew that he was the traitor; she replies that he was the only survivor left, as Umbrella wouldn't kill their operatives unless they needed to. Doc begs her not to kill him, but she instead gives that opportunity to Claire. He reasons with her, saying that he was forced to work for Umbrella, but Claire shoots him in the head instead, killing him.