On the planet Inter Minor, two silver-skinned aliens watch a cargo ship arrive. A mute race of Functionaries unloads the cargo. The cargo includes Vorg, a flamboyant con-man, Shirma, his pretty assistant, and an elaborate device called a Miniscope. A Functionary tries to agitate his fellow workers, but is quickly stunned by Kalik, one of the officials.
The Doctor is taking the TARDIS on its first flight since his traveling ability was restored. He has aimed for Metabilis Three but he and Jo land in the hold of a ship.
Vorg tries to draw people in to watch his "carnival of monsters" but Kalik is suspicious of him. A warning light begins to flash on the Miniscope.
The Doctor and Jo find chickens in the hold and crates marked for Singapore. They head up to the deck to find out where they are. They appear to be on an Earth ship, but the Doctor remains suspicious.
They find passengers aboard: an old Major, his daughter Claire and a young officer named Andrews. Claire and Andrews go for a walk around the deck while the Major stays to read a book. The Doctor and Jo wait for the Major to fall asleep and sneak out. Jo shows the Doctor an Earth newspaper but he's still convinced they are not on Earth.
Suddenly, they hear screams. A plesiosaur rears its head outside and then vanishes. The Doctor and Jo try to sneak out in the confusion but are caught. Andrews and the others believe they are stowaways.
Pletrac, one of the alien leaders, joins Kalik at the spaceport. They discuss the Functionary problem.
The Major is friendly to the Doctor and Jo, but Andrews wants to confine them for the time being. On their way to a cabin, the Doctor find a silver hexagonal hatch. Andrews and the others can't see it.
The Doctor finds out that the ship is the SS Bernice. He tells Jo that the Bernice vanished without trace on June 4, 1926 — today's date. Jo notices that the clock has changed time, shifting back two hours. The Doctor begins to tinker with the cabin lock but Jo reveals that she has a skeleton key.
Pletrac inquires about Vorg and Shirna, confused about what exactly they do. They wonder if entertainment would pacify the Functionaries but decide to make the entertainers leave the planet. Vorg tries to pretend he has permission from the President to be there.
The Doctor decides to get some tools from the TARDIS to open the hatch. On their way, they hear the passengers repeating their conversation from earlier. The Doctor realizes that the ship is part of an alien collection, trapped in time. Soon after, the plesiosaur attacks again. This time, they are able to sneak past the Major and Claire.
The Doctor and Jo reach the TARDIS. As they do, a giant reaches down and picks up the time vehicle…