You find yourself on planetoid TG-88.3Ω, otherwise known as "The Hollow Planet". A rogue Dalek has knocked out the local android population and taken over the mining facility built long ago on the planet’s surface and players must work to help take back control of the planetoid before it’s too late.
2-6 individuals are sent a message by the Thirteenth Doctor, asking them to help investigate TG-88.3Ω, a dwarf planet that was once rich in metal ores but has since been extensively mined, leaving it just a hollow shell. The Doctor explains that the planet's mining robots and control facility have been taken offline by an unknown entity.
The recruits enter the facility via an air vent on the building's roof, while the Doctor heads down inside the planet, following a signal that the occupying force is beaming directly into the hollow core. She captures a snapshot of the message, and identifies it as a Dalek language, but one that the TARDIS is unable to translate. Meanwhile, the recruits meet Graves, the control facility's holographic penguin assistant, who offers to tour them around the facility – except for the Control Hub, which is occupied by a Dalek.
Per the Doctor's remote instructions, the recruits travel around the facility, repairing some damaged systems and collecting information that allows them to translate the message the Dalek is beaming into the hollow planet. Deciphered, it reveals that the Dalek is alone and alarmed by the presence of the Doctor, with the planet's concave interior serving to beam the distress message across the galaxy.
Seeking to get the Dalek off-planet before any reinforcements can arrive, the Doctor instructs the team to use the Control Hub's electrostatic floor tiles to forcibly manoeuvre the villain into the facility's trash ejector chute. They succeed, and launch a trash ejector pod containing the Dalek into space. The mission complete, the Doctor prepares to take the group back to Earth, and suggests that they could leave TG-88.3Ω's mining robots disabled, allowing the hollow planet to remain at peace.