Dr. Elizabeth McNeil

Dr. Elizabeth McNeil first appears as a background character in Doom 3 and then returns as a main character in its expansion, Doom 3: Resurrection of Evil. She was a UAC Mars Facility Delta Labs researcher who blew the whistle on Dr. Betruger's activities in Doom 3. She asks the UAC board to send Elliot Swann and Jack Campbell to the base to investigate the experiments Betruger is running. Although she is not seen in Doom 3 due to Betruger sending her off the planet for her actions, her PDA is left behind in her office and details her response to the experiments going on in the base as well as the actions she takes in response.

Elizabeth McNeil is voiced by, who is best known for doing the voice of the female version of Commander Shepard in the ' game series, and the vocalizations of Samus Aran in the ' trilogy.

Doom 3
Dr. McNeil is first mentioned in Doom 3, where a message from her can be found in the PDA of Theresa Chasar, who transforms into a lost soul. McNeil's own PDA can be found in the Delta Labs and contains an e-mail from Elliot Swann informing her that he is coming to Mars to investigate her concerns about Dr. Betruger.

McNeil was friends with Theresa Chasar, as the two were some of the few female UAC employees on Mars. She was also colleagues with Dr. Pierce Rogers, and at one point had a disagreement with him - probably having to do with her concerns about Betruger's work. After the invasion, Rogers tried to send her a message apologizing for not listening to her, and telling her that Betruger was mad and that this evil must not be allowed to spread to Earth. The message could not be transmitted however due to the extensive damage to the facility. It is unknown if McNeil ever received this message in the aftermath of the invasion.

Doom 3: Resurrection of Evil
McNeil appears in Resurrection of Evil as the player's commander and source of tactical intel. Elizabeth was assigned in the abandoned Mars facility to lead the primary assessment of the abandoned research facilities on Mars. She is first seen in the command center asking a marine about the status of the recon squad, including the protagonist, in the underground ruins beneath the base. During the invasion she was able to escape the Erebus facility and get to a sealed office in Phobos Labs. She informs the marine protagonist of the situation and orders him to rendezvous with her in the labs. When the Marine gets there, Elizabeth informs him of the true nature of The Artifact, a one way portal generator from Hell. According to ancient Martian writings found and deciphered in the ruins, it can only be destroyed by bringing it to its source in the next world. McNeil determines that four system generators must be shut down in Phobos labs in order to bring a teleporter to Hell online. By this time, McNeil had also discovered Betruger's command of the new invasion.

Late in game, Dr. McNeil orders the marine protagonist to shut down life support systems to the base in order to power the teleporter long enough to allow the marine to get to Hell. She selflessly declared that their mission is "more important than any of us." Soon after this, the Marine loses contact with her, with her last radio transmission cutting off abruptly. In a final cutscene the screen fades to white, and McNeil can be heard saying: "Marine...? Marine... Welcome home," possibly implying they are both in a better place after having sacrificed themselves for humanity.