When Harry heads home, a young woman named Lettice Butts collides with him. She is being followed and asks him to take her home. The two men following her, Abel Crumpton and Mr Cruncher, are looking for the Egg.
At Lettice's flat, she convinces him to deliver an envelope for her. He leaves with the envelope, and realises he left his coat in her flat. Before he can make up his mind whether to go back and get it, he is hit from behind.
In her flat, Lettice is packing. She speaks into an ariel on the suitcase. Someone is telling "Agent" Butts to take care. She hears a noise and, seeing Harry's coat, assumes he has come back for it. She opens the door, and armed men storm into the room.
When Harry regains consciousness, he is confronted by Crumpton, who believes Harry knows all about the Egg. When Harry can't answer his questions, Crumpton has Mr Cruncher beat Harry. Harry is then taken to a storeroom. Suddenly a mechanical mole-machine bursts through the floor and urges Harry to get in.
Harry has been rescued by a man named Radcliff. He and Lettice are all that's left of the people of Zantor, a planet that was annihilated by a ruthless Garvak named Abel Crumpton. The Egg is a seeding device with the genetic template of all life from Zantor. Lettice and Radcliff want to use it to seed a new planet; Crumpton wants to destroy it.
Harry agrees to help Radcliff retrieve the Egg and rescue Lettice, who Crumpton needs to unlock the Egg. Radcliff takes Harry to the secret base of DOCTO(R), the Department of Overt and Covert Tactical Operations (Regional). They are briefed by Emily Dunkirk and proceed to trace the Egg to Switzerland, Mexico City, Rio, Shanghai and finally Belgium.
First they rescue Lettice, who takes them to where the Egg is being kept. On the way, Harry, with his stomach rumbling, stops at the canteen.
Crumpton's guards catch them outside the Egg chamber. They are brought to Crumpton, who has a ceremony planned and intends to use the Egg to replace the DNA matrix of the Egg and create a Garvak Empire on Earth.
When he hooks the Egg up to a machine, it explodes in a mess of white and yolk. Harry has replaced the Egg with an egg. Crumpton's machine creates a feedback loop, and the machine starts to focus its power on the assembled Garvaks and turns them into chickens. Harry, Lettice and Radcliff leave the building, which then bursts into flame.
Lettice and Radcliff depart in their ship with the Egg. When Harry tries to tell the story to Chumpy and Buffy, they laugh at him in disbelief.
- Harry Sullivan
- Chumpy Withers
- Buffy Worthington
- Lettice Butts
- Abel Crumpton
- Mr Cruncher
- Emily Dunkirk
- While being briefed by Emily, Harry makes egg-related puns, asking if a transmission was scrambled and asking what kind of plot Crumpton is hatching.
to be added
- Harry tells his friends that the potato-heads have a vent in the backs of their necks. (TV: The Sontaran Experiment)
- Harry tells his friends about the adventure with the time ring. (TV: Genesis of the Daleks)