Dilmer III is a pre-industrial planet where a week passes for every second aboard the Cerritos, trapping three officers there for a year.
Dilmer III is a pre-industrial world subject to extreme time dilation, so that a week passes on the surface for every second that passes on the Cerritos. In Fully Dilated, Mariner, Tendi and T'Lyn go undercover there to stop the locals from discovering stray technology from a parallel universe, the head of an alternate Data.
When the transporter breaks, the three spend a year on the planet during the minute repairs take. Tendi reactivates Data's head, T'Lyn improves local agriculture, and the suspicious villager Snell tries to expose them as witches.