Planet of the Daleks ( TV story ) Planet of the Daleks was the fourth serial in season ten of " Doctor Who " . It was the conclusion of a loose , dual - serial storyline begun in " Frontier in Space " . It was also a direct sequel to the very first Dalek serial , showing what had happened to the Thal s after the First Doctor met them in " The Daleks " and the heroic legacy the Doctor left on their culture . Behind the scenes , it was writer Terry Nation ' s first " Doctor Who " commission since the 1965 Christmas episode , " The Feast of Steven " , and director David Maloney ' s first story since " The War Games " . Synopsis . Arriving on Spiridon , the Third Doctor and Jo encounter a Thal group . But the Dalek s are here . . . and this time , they ' re invisible . Plot . Episode one . The Third Doctor has been shot and gravely wounded by . Jo helps him into the TARDIS , where he uses the telepathic circuits to send a message to the Time Lord s before he collapses . Delirious , he tells Jo that he may be asleep for a while . He falls into a coma , his body temperature dipping so low that frost appears on his skin and both his heart s beat only once every ten seconds . Jo dictates into the TARDIS log , a portable recording device , that she has seen this healing state before . She states that the TARDIS is moving , apparently being controlled remotely by the Time Lords . When it halts , Jo activates the external scanners , only to see plants outside . They block the viewer by spraying a thick , sap - like liquid at it . With the Doctor catatonic , Jo leaves the ship to explore the surrounding jungle . The plants spray sap on her as she walks by . Some of it gets on her exposed hand . As Jo explores , the TARDIS is rapidly covered by plant sap , hardening into a shell around it . When the Doctor awakens , he finds himself sealed in . The oxygen in the TARDIS cabin is rapidly being used up . He activates the emergency oxygen supply and finds the tanks almost empty . He starts to suffocate . Jo , in the meantime , discovers a spacecraft in the jungle with a dead pilot . She is found by two others in the same uniform — Taron , who appears to be the leader , and Vaber , who has a surly disposition . Taron is intrigued when Jo tells him about the TARDIS . They are joined by another crewmember , Codal , who warns them a patrol is approaching . Taron tells Jo to hide in the spacecraft while he and the others find her friend . Jo hides in a storage cupboard while an invisible entity enters and searches the craft . She avoids discovery , but a fungoid growth has appeared on her hand and is starting to spread . Taron and his men find the TARDIS and chip the hardened sap from its doors , dragging the nearly asphyxiated Doctor outside . The Doctor thanks them and notes he finds them familiar . When the men say they are from the planet Skaro , the Doctor recognises them as Thal s and tells them he was on Skaro many years ago . The Thals are sceptical when he claims to be the famous Doctor of Thal legend , but he gives them enough details to mollify them . Taron tells the Doctor that he has been infected by a fungus carried by the sap and treats him with a spray . It would have engulfed and killed him had Taron not done so . They are on Spiridon , a planet where the plant life is more animal than vegetable . There are creatures hostile to everyone , including themselves , and extremes of day and night temperature . These Thals are the only survivors of a military expedition . Taron orders a halt to their progress through the jungle when they hear something breaking down . Nothing is seen except a circular depression in the ground . Giving the Doctor another spray can , Taron tells him that he will see what they are up against . The Doctor sprays the seemingly empty air before him . It reveals the outline of a Dalek . . . Episode two . The Dalek is inactive , dead from what the Thals call " light wave sickness " . The Spiridons , the dominant species on the planet , can generate an " anti - reflecting light wave " , which the Daleks are trying to duplicate . However , it takes a tremendous amount of power and cannot be long sustained . The Spiridons have been subjugated and enslaved by the Daleks , but there are no more than twelve Daleks on the planet . Back in the spaceship , Jo has passed out as the fungus spreads across her forearm . An invisible Spiridon enters the spacecraft and takes her away . A Spiridon patrol comes across the Thals and the Doctor . Codal leads them away from the others but is captured . When they make it back to the craft , they find the TARDIS log on the ground and two Daleks about to destroy the ship . Believing Jo still inside , the Doctor steps forward and begs the Daleks to stop , but the patrol shoots him with a stun ray . He watches helplessly as the spacecraft is blasted to pieces . Taron and Vaber remain hidden and go off to retrieve the supplies for their mission on Spiridon . The Doctor is taken to the Dalek base for interrogation and put in the same cell as Codal , whom he tries to cheer up . The Doctor tries to open the cell door with his sonic screwdriver , but to no avail . Codal and he decide to modify the components of the TARDIS log to emit a radio frequency to jam Dalek control impulses . Meanwhile , Jo is being cared for by the Spiridon who found her . His name is Wester and he is one of a group of his people who are trying to fight back against the Daleks . He cures her of her fungal infection with a salve and tells Jo that the Doctor and Codal have been captured and taken to the Dalek base . Jo is determined to free them , even though Wester says that if the Daleks use them for their experiments , they are better off dead . Vaber and Taron find the explosives that they hid earlier . Vaber wants to attack the Daleks now . He accuses Taron of being overcautious and cowardly when Taron refuses . Vaber draws his gun and threatens to shoot Taron if he does not hand over the explosives , but before things can get out of hand the heat and roar of another spacecraft rush over their heads . It is another Thal vessel , but the entry angle is too steep , and their weapons are lost in the crash that follows . Only three Thals have survived — two men , Latep and Marat , and a woman , Rebec . Taron is unhappy to see Rebec . She happens to be his lover . Rebec tells him that they intercepted a message to Dalek Supreme Command saying that the Dalek army on Spiridon was now complete : a force of not a dozen , but ten thousand Daleks . Episode three . Jo and Wester see fur - wearing Spiridons entering the Dalek base , carrying crates of vegetation . The Daleks are experimenting with a plant - destroying bacterium . Jo hides on one of the crates and smuggles herself into the base . Taron shows Rebec another feature of Spiridon — a liquid allotrope of ice that exists in the core of the planet and erupts to the surface like lava . The Daleks use it as a cooling system , with ice tunnels that lead into the base . Taron plans to use them to infiltrate and cause a distraction while Vaber and Latep wait by the entrance with the explosives . A Dalek is sent to interrogate the Doctor and Codal , who use the improvised jamming device on it successfully , but the device is destroyed in the process . Making their way through the corridors , they find the three Thals , who are struggling to get out of the tunnels before a molten ice eruption floods them . Jamming the shaft doors open and getting them out , all run as a Dalek patrol enters the corridor and is covered by the molten ice rushing out of the cooling tunnel . The rest stumble into a chamber while Marat , weakened from the cold , covers their retreat . He is exterminated by the Daleks , who find a map on him showing where the explosives are hidden . The Doctor seals the doors with his sonic screwdriver . The Dalek Section Leader sends a patrol to find and destroy the explosives , while others are sent for cutting equipment . Jo overhears the orders and follows the Dalek patrol out of the city . Trapped in the chamber , the Thals and the Doctor find a huge refrigeration unit pumping excess heat up through a ventilation shaft that leads to the surface . The Doctor also discovers the Dalek army stored in an adjoining chamber , sleeping in suspended animation . The four improvise a hot - air balloon from plastic sheeting but there doesn ' t seem to be enough lift to carry all of them , and the Daleks have nearly cut through the door . . . Episode four . There is finally enough lift for the improvised hot air balloon to carry the Doctor and the Thals up the shaft . They rise up out of the room just as the Daleks break through the door . A gravitational disk is sent for so that a Dalek can follow them up the shaft , while another patrol is sent to the shaft ' s exit on the surface . The Dalek patrol sent for the explosives activates the timed detonators and leaves . Jo sneaks up to try to deactivate the timers but only manages two before being knocked out by a stone from the crumbling cliff - face the explosives were hidden against . She awakens barely in time to grab the deactivated bombs and take cover before the third goes off , conveniently destroying the Dalek patrol sent to intercept the Thals . Meanwhile , the Thals and the Doctor reach the top of the shaft and drop a rock on the pursuing Dalek , sending it plummeting to the bottom . Making their way away from the shaft , they meet Jo , whom the Doctor is overjoyed to see again ; he thought her killed when the Thal ship was destroyed . The Doctor explains that his telepathic signal was to tell the Time Lords the location of this planet — he had learned that there was a Dalek invasion force here while on the planet of the Ogrons . The Time Lords steered the TARDIS here . Latep and Vaber also rejoin the group . They had thought the others were killed in the ice eruption and were about to assault the city when they found one of their bombs was a dud and the others destroyed by the Daleks . Jo shows them the two bombs she rescued . The group decide to hide in the Plain of Stones , an area of Spiridon with rocks that absorb heat from the sun by day and discharge it at night . They avoid a combined Dalek / Spiridon patrol as night falls and the temperature drops . The Doctor notices the Daleks seem to be moving slower than usual . In the Dalek base , one reports to the Section Leader that the bacteria will destroy all plant life within a day and unimmunised life forms within an hour . It will be ready in half a Spiridon day . At the Plain of Stones , Vaber and Taron come to blows again about when to take action . During the night , Vaber steals the two bombs and sneaks away from the camp . Taron and Codal go in pursuit as the others huddle around the campfire , surrounded by anima with eyes glowing in the darkness . Vaber is caught by the Spiridons , and the leader tells them to take him to the Daleks . . . Episode five . Taron and Codal disguise themselves as Sprirdons and get into the group . They arrive and meet with a Dalek . The Dalek tries to force Vaber to lead them to the Thals . Vaber pretends to cooperate , but he breaks away and is exterminated . Taron and Codal use this distraction to grab the two bombs and vanish into the forest . The Daleks have developed an immunisation process against the bacteria . Orders are sent out for all Daleks and Spiridon slaves to return to the base for immunisation before the bacteria is released . On the Plain of Stones , Wester shows up to tell Jo that the Daleks have developed the deadly bacteria , and he is going to try to enter the base and stop its release . The Doctor devises a plan using nearby pools of molten ice . Deducing that the ice slows and even stops the Daleks from functioning , the group lure a Dalek patrol to them and push the two Daleks into the pools . The sudden drop in temperature kills them . Taron , Codal and the Doctor dress in Spiridon furs while Rebec sits in the emptied Dalek casing so they can enter the base undetected with one of the bombs . Latep and Jo will enter the city via the ventilation shaft with the other bomb , in a two - pronged attack . As the first group enters the city , they see Wester entering the bacteria preparation chamber under the pretence of delivering a report . Wester releases the bacteria into the sealed room , sacrificing himself , but ensuring that the room cannot be unsealed without killing the other Daleks . The group try to move deeper into the base , but one of the Thals ' boots is spotted by a Dalek , who sounds the alert . Episode six . The group flees down the corridors , making their way back to the cooling chamber . Once there , the Doctor asks Rebec and Taron to barricade the entrance while he finds a way to keep the Dalek army from reviving . Codal and he decide to set an explosive in the wall of the chamber holding the Dalek army , which are slowly coming to life . In the meantime , the Dalek Supreme , a member of the Dalek High Council , has arrived in a spaceship to oversee the final stages of the operation . It exterminates the Section Leader for incompetence . Jo and Latep finally arrive at the cooling chamber and use their bomb to destroy a squad of Daleks before joining the others . As another patrol comes through , the bomb set in the chamber wall explodes . Molten ice rushes out to flood the chamber , freezing the Dalek army for centuries to come . The group escapes over a ramp that leads to the surface , while the rest of the Daleks abandon the base , which is filling with molten ice . The group makes its way to the Dalek Supreme ' s spacecraft . The Doctor asks Taron not to glorify what has happened , nor make war sound like an adventure . The Thals were a peaceful people , and he would hate to see them change . Taron and Rebec promise , and the Thals enter the spacecraft and leave for Skaro . The Doctor and Jo run back to the TARDIS , pursued by the Dalek Supreme and the other Daleks . They dematerialise just as the Daleks open fire . The Dalek Supreme orders operations to recover the invasion force and contact the Dalek High Council for a rescue ship . The Daleks have been delayed but will never be defeated . . . Home video and audio releases . DVD releases . This story was released on 5 October 2009 with the previous story , " Frontier in Space " in a boxed set called " Dalek War " . It features a re - colourised Episode Three , commentary and numerous special features . Audio release . The story was also recorded and released in audio format .