In a parallel universe, Eric Vollmer was a scientist researching renewable fuels. He knew of the Doctor, and thought that he'd been referred to Vollmer thanks to a fellow scientist, but this was a ruse by the Doctor to gain access to the DEEP's records so he could find out if his suspicions of Lee's experiments were justified.
In 2039, he was used as a scapegoat. He was mutated in the experiments that his assistant Lee conducted and had already began to change. He wanted to go with the Doctor on the submersible aboard the DEEP but the Doctor shot him to ensure Lee's experiments would not be able to be continued. (AUDIO: Full Fathom Five)