Dr. Isabel Cho was one of the four survivors from the USG O'Bannon incident.
Isabel Cho was the Chief Medical Officer on board the USG O'Bannon. She was one of the few crew members besides Nolan Stross, Rin, Nickolas Kuttner and Captain Caleb Campbell to know about the true intentions of the mission which involved gathering any remaining Marker fragments from the colony on Aegis VII.
The crew landed on an unstable Aegis VII and headed out to look for the surviving fragments of the Red Marker. Kuttner found one of them and started to hallucinate Cho and her teammates as monsters and going as far as killing Alejandro Borges' cousin, Noah Pawling. Cho tried to save Noah, but it was too late. The structurally unstable Aegis VII began to explode and only her, Stross, Borges and Kuttner survived, crashing back into the O'Bannon and eventually giving the Marker fragment to the Captain Campbell.
Cho took care of a very confused and disorientated Kuttner while overseeing the bodies of all of those that are killed on Aegis VII. Cho and her medical team went to check on the bodies to reveal that all of them are gone and the mutilated corpse of one of the doctors soon transformed into a Necromorph and killed all except Cho. Cho made it to the room where Kuttner was being held and released him before he killed the Necromorph. Isabel and Kuttner made it to Stross' suite to discover that he killed his wife, Alexis and his baby son in his hallucinations. Cho was horrified by this and began to bitterly refuse to have conversations with Stross.
Isabel, Stross and Kuttner are reunited with the Captain Campbell, Alejandro and the other two crew members, Lt. Marcus and Lana and discovered that the shard could only be destroyed if they could throw the fragment into the reactor core. The team set off toward the engine room, but Lana has noticed her roommate, Jenny who was ignoring Cho's warning about getting too close to the Necromorph. As Lana got close enough, Jenny was already turned into a Grabber and spat acid into Lana's face. The skin on Lana's face was dissolved, but despite her horrific injuries, she survived the attack. She later died due to a grenade blast. Lt. Marcus was soon after killed when a Necromorph attacked him which led to him being sucked out of the hull's breach and into space.
Kuttner was almost sucked out of the ship as well, but was reluctantly saved by Borges. After the remaining survivors made it into the airlock, Stross gave them the unfortunate news that the airlock's seal was broken on their side and it could only be sealed from the outside. Feeling guilty and responsible for all of the deaths of his crew on Aegis VII and on his ship, Captain Campbell volunteered to be the one to seal the airlock. After arguing with his remaining shipmates, the Captain Campbell ordered them to destroy the shard.
As he exited the airlock, he told them to tell his wife that she was right and he should have retired before journeying to Aegis VII. After sealing the doors, he pulled out an incendiary grenade and jumped into the crowd of Necromorphs and caused a second hull breach outside of the sealed door, causing all of the remaining Necromorphs to fly into space. Cho collapsed as the Captain Campbell sacrificed himself to save them. The group made it to the engine room just to be attacked by several Necromorphs. Cho managed to keep them at bay, but Stross once again became hypnotized by the fragment which Cho responded by running up to him and punching him. Cho grabbed the fragment and before it could have any effect on her, she tossed it into the core, destroying it and all of the Necromorphs which turned into small puddles of what was described as "organic soup" by the other witnesses.
Discovery and Interrogation
A squad of five Marines entered the O'Bannon to discover that all of the crew members are dead except four. The guards took Cho, Stross, Borges and Kuttner and took them aboard the USM Abraxis. After Borges and Kuttner did not return from their interrogations, Cho began to worry just before Stross replied by telling her that they are dead as he could "feel" it. Stross was next to be interrogated before Cho. After Isabel was interrogated, she was confronted by a member of EarthGov, the Overseer who offered her a job. Cho was horrified by this and declined, telling him that she would not stand for this as they had the whole event planned all along. The Overseer told her that he was sorry that she felt that way before she was grabbed and lobotomized in order to keep her quiet.
At the Sprawl
Cho was used as a scapegoat by the government in order to cover up the events that transpired on Aegis VII. The public was told that Cho was a terrorist that massacred the crew on Aegis VII, the USG Ishimura and the USG O'Bannon and she was held at the Sprawl to be tried for her "crime".
It was unknown what happened to Cho afterward. It was possible that she was found guilty for her "crimes" and imprisoned, executed or possibly used to experiment on by EarthGov. Even if she was kept alive, she would likely have been killed during the Necromorph outbreak on the Sprawl, but there was no evidence that she was on the Sprawl during the outbreak and it left her fate in question.
- Isabel Cho was voiced by Gwendoline Yeo and her CGI-animated character was also based on her likeness.
- The Lead Interrogator told Cho that she had a fine mind and a strong will, indicating that her mind could have been as pure as Isaac's had she came into contact with the Marker shard.
- It was suggested that Cho had a Korean background as she stated that she could only speak English and Korean.
- Cho was involved in an affair with Nolan Stross for seven months. Stross told Cho that he was going to leave his family, but Cho tried to distance herself from Stross for this reason, ultimately failing due to the fact that she loved Stross too much and she was too happy with him to give up even knowing that he had a wife and child.
- Cho's appearance differed in each scenario.
- Cho was one of the five female protagonists of the Dead Space series besides Alissa Vincent, Lexine Weller, Karrie Norton and Ellie Langford.
- Unlike the other three survivors of the O'Bannon, Isabel's exact phobia was never revealed as it just skipped over to the scene where she was gasping for air. This may be hinting toward hydrophobia or a rape scenario.
- In Dead Space 2, she was only mentioned in the name of an audio log.
- In the falsified news report branding her a terrorist, an image of her was shown with a blank expression and a red spot on her forehead which was the evidence of her lobotomy.