Mariner, Tendi and T'Lyn spend a year undercover on a pre-industrial world where time runs far faster than on the Cerritos, guarding Data's severed head from discovery.
Mariner, Tendi and T'Lyn go undercover on Dilmer III, a pre-industrial planet where a week passes for every second aboard the Cerritos, to keep the locals from finding technology from another universe: the severed head of the android Data. When Boimler and Rutherford accidentally disable the transporter, the trio must live on the planet for a year while the repair takes a minute of ship time.
Believing she and T'Lyn are competing for the senior science officer post, Tendi tries to outdo her and reactivates Data's head, while T'Lyn introduces farming improvements. They discredit a suspicious local who accuses them of witchcraft, and back on the ship Data advises Freeman to promote both women before returning to his own universe.