Examining the Pod

After leaving the planet Karn (see "The Brain of Morbius") The Doctor and Sarah Jane Smith return to Earth. On visiting UNIT The Doctor and Sarah meet Richard Dunbar, an unscrupulous politician working for the World Ecology Bureau. He informs them that a research team in the Antarctic have recovered a strange, unidentified vegetable pod that has been buried in the ice for some 20,000 years.

The Doctor suspects it is alien in nature and insists that the research team in the Antarctic must not to touch it until he arrives. When The Doctor and Sarah arrive, at the Antarctic base, The Doctor’ suspicions about the pod are proved correct. The pod is from the Krynoid, an alien vegetable which feeds on a host planet's animal life until that planet is dead and then sends its spores out into space where they fall to other worlds to germinate. To The Doctor’s horror in the course of investigating the pod, the scientists in the Antarctic had fed it, causing it to germinate, taking over the body of one of their team. As the scientist slowly mutates into a Krynoid, so its lust for blood grows and it escapes, running wild in and around the base.

News of the pod is also leaked, by Richard Dunbar, to botanist and plant collector Harrison Chase whose estate is filled with thousands of plants. Harrison Chase, who considers it his mission to protect all plant life on Earth, decides that he has to add this unique, and possible extraterrestrial, specimen to his collection. He therefore despatches his henchman Scorby and botanist Arnold Keeler to bring the pod back.

Richard Dunbar and Harrison Chase

On arriving at the Antarctic base they take possession of a second pod which had also been discovered and set explosives to destroy the base before returning to England, leaving Sarah tied up inside a generator hut with the bomb. The Doctor discovers Sarah and unties her but before The Doctor can diffuse the bomb the Krynoid arrives as well. They manage to get out through the door and lock the Krynoid in. As they run for cover the hut explodes, killing the Krynoid but also destroying the rest of the Antarctic base with it.

The Doctor and Sarah then return to London. Following the trail of the second pod they trace it to Harrison Chase's mansion. They gain access to the grounds with the help of Amelia Ducat, an ageing painter of flora, but are caught by the patrolling guards. Harrison Chase realises that he has to investigate what Arnold Keeler and Scorby have told him about the infected human at the Antarctic base, and arranges for the pod to be germinated under controlled conditions while a human host is forcibly held nearby. Unfortunately that host is Sarah. Harrison Chase has decided to have Sarah infected by the Krynoid pod. As the experiment takes place Sarah is brought into a room and forced to sit close the Krynoid pod, which starts to open.

Scorby

The Doctor rescues his companion in the nick of time, but Arnold Keeler is less lucky and is infected by the plant. His transformation into a Krynoid is then accelerated by Harrison Chase who arranges for him to be fed with raw meat. Growing in strength, the Keeler-creature eventually escapes from captivity and goes on the rampage through Harrison Chase's estate.

Horrified at what has taken place Richard Dunbar tries to make Harrison Chase see sense. But he fails and is forced to flee through the grounds of the mansion chased by Scorby. He suddenly comes across the Krynoid, now about ten feet tall and totally inhuman. He is killed, but his scream alerts The Doctor and Sarah, who run to help but the creature then surges towards them.

With the Krynoid rapidly growing larger, and becoming stronger, by the hour The Doctor and Sarah also discover that all the nearby plants are being controlled by the Krynoid. The Doctor manages to gain the assistance of UNIT. But Sarah becomes trapped within Harrison Chase's greenhouse and is nearly suffocated by the Krynoid-controlled plant. The Doctor, however, with the help of a soldier arrives and they start to spray weed-killer on the Krynoid-controlled plants in an attempt to destroy them. This allows them to reach and free Sarah.

Sarah Jane Smith

As the plants can communicate with the Krynoid, The Doctor decides to move all the plants outside but Harrison Chase locks the door behind them and they find themselves trapped outside as the giant Krynoid approaches. Luckily more UNIT soldiers, led by Major Beresford, arrive and they open fire with a Laser gun, distracting the Krynoid, so allowing The Doctor and his group to reach another door and the relative safety of Harrison Chase’s mansion.

Inside the mansion The Doctor soon discovers that Harrison Chase is now totally insane and in retribution for the destruction of all the plants he decides to turn Sarah, who has been rendered unconscious, into compost for his garden by feeding her into a pulverising machine. The Doctor arrives just in time to rescue her and switches off the power. But after freeing Sarah, Harrison Chase sets the machine going again and attacks The Doctor. As the two struggle inside the machine's bin The Doctor manages to climb out so escaping a grisly fate, but Harrison Chase is not so lucky and is pulled into the machine despite The Doctor’s efforts to save him.

Meanwhile outside the Krynoid has now grown to giant proportions, dwarfing the house. UNIT therefore arrange for the RAF to bomb the Krynoid before it can pollinate and spread its pods across the Earth. The Doctor and Sarah however, are still trapped in the house unable to escape due to the Krynoid-controlled plant life covering the house. Realising they have very little time before the RAF arrive The Doctor rigs a steam pipe to blast their way out. They then make their way through the hostile plant life and take refuge in a clearing just as the RAF bomb the house so destroying the Krynoid.

With the crisis over The Doctor decides that they need a holiday on the planet Cassiopeia. But much to Sarah's dismay instead of arriving somewhere sunny and warm, as expected, the TARDIS takes them back to the cold and snowy Antarctic.