The Doctor discovers the plastic daffodils are designed to fire a spray that asphyxiates people, causing havoc prior to the Nestene's arrival, but before he can alert anyone he and Jo are captured by the Master.
The Doctor and Jo head to Stangmoor Prison to investigate the Keller Machine, which drains the evil impulses from prisoners' minds, while UNIT are handling security at the first world peace conference.
Realising Chin-Lee has been using the power of the Keller Machine to carry out assassinations, the Doctor heads back to Stangmoor, only to find the Master has teamed up with Mailer to stage another riot.
The Time Lords takes control of the TARDIS and the Doctor and Jo arrive on a Earth Colony in the 25th Century, where a ruthless mining company are using a dinosaur-like creature to force the colonists to leave the planet. Where the Doctor and Jo learn that The Master is on the planet and is in search of a doomsday weapon that is hidden somewhere on the planet.
The Doctor and the Master are taken into the Primitive city, where the Master hopes to find the doomsday weapon, while Dent forces the colonists to leave the planet even though their ship is likely to explode.
The Doctor explains to his friends that the Master is trying to gain the power of the last of the Daemons, a race who influenced Earth's development, while the Master brings the rest of the village under his control.