Peter Stevens
was an engineer and doctor, the creator of the cold sleep capsules used by Kasumi and the other people gathered by Venus Gate. Despite his success in creating stable prototypes of the capsules, a sudden crisis of the electronics market left him without financial support, until Venus Gate expressed interest in his project and hired him and his colleagues.

Again backed up, Peter succeeded in developing cold sleep capsules and gained access to most of Venus Gate's labs, though he never clearly understood what the mysterious Level 4 was for. However, after developing the capsule he was suddenly withdrew from the project, which was in turn passed to Level 4 and left him bitter with resentment, so much so that his only obsession became to retrieve his cold sleep capsule from Venus Gate. He apparently succeeded in discovering the Level 4 data, though in doing so he was discovered and took prisoner, after which he was infected with Medusa.

While awoken with the other survivors, Peter turned traitor on them when he took Kasumi with himself (this being a mind-planted instinct forced by Zeus) and searched for the laptop containing the downloaded files. He paid this search with his life when the room where he was suddenly crumbled on him, killing him shortly before. Nevertheless, as he was infected with Medusa, he managed to come back to life as a twisted being filled with insects and cockroaches. Taken prisoner while trying to get back his original, first cold sleep capsule, he was killed by Zeus when he tried to attack him.