Gagan Rassmussen

Professor Gagan Rassmussen was a scientist in the 38th century.

He had developed Morpheus pods on the Le Verrier space station in which people would lie inside for five minutes, giving them a month of rest, using a carrier signal to effectively rewrite the centres of the human brain responsible for sleep. The pods were developed as tools of business to make workers more productive.

Gagan wanted to make enhancements to the process and worked on producing improved pods; however, these new sleep pods concentrated the buildup of rheum in the users eye, which evolved into a carniverous, intelligent organism identified as Sandmen when stimulated by the Morpheus pods' signal. While testing these pods, Gagan and his crew became unwitting hosts to Sandmen, which subsequently gained sentience and consumed them in their sleep. The dust preserved Gagan's human form, and impersonated him.

'Rassmussen' plotted to spread the encoded signal the Morpheus pods used to create Sandmen across the solar system. In doing so, he orchestrated a scenario filled with plot twists and a climax on board for dramatic effect "like a story", and send a video of this story with the signal.

In this staged story, Le Verrier went silent, and a rescue team from Triton, as well as the Twelfth Doctor and Clara Oswald, arrived. Looking for the crew, they find Rassmussen hiding in a pod. Rassmussen gave a fabricated explanation the situation, where he survived by hiding in the pods, and begged them to get him off the Le Verrier. However, the rescue team insisted on investigating further, and Rassmussen was seemingly killed by a Sandman in the course of their investigation.

After being discovered apparently alive again afterwards, Rassmussen claimed the Sandmen had made it very clear to him that they were "the future" and "a better life form", that they spoke to him in his mind, and he lied that they had spared him. He then claimed that his plan was to spread the infection of the sandmen via transporting one of the sandmen across the galaxy. He appeared to die again when Nagata, the commander of the rescue team, shot him. At the end of Rassmussen's video when Le Verrier's gravity shields were destroyed, he revealed the truth - Rassmussen had indeed been consumed by the Sandmen, who used his form to create a narrative that would keep the viewers watching, and thus expose them to the Morpheus signal hidden in the video interference running throughout. He then suggested the viewers share what they have seen so that all humanity may come together, "dust to dust", before disintegrating. (TV: Sleep No More)

The footage that Rassmussen recorded was later used in the episode of Doctor Who entitled Sleep No More, which was broadcast in late 2015, and was available on BBC iPlayer by 2020. (WC: The Zygon Isolation)

Behind the scenes
Rassmussen is one of the Sandman enemies in the Doctor Who: Legacy mobile game.