Synopsis: Injured from his confrontation with the Master, the Doctor collapses in the TARDIS. Having sent a warning to the Time Lords, the TARDIS takes off on its own. He then enters a healing coma, as he had done so twice before. Jo watches over him anxiously as he recovers, and then the TARDIS lands. Concerned about the Doctor, she exits into the thick jungle outside to look for help. She finds that the plants nearby are spraying sap and some of it gets on her.
Not long afterwards, the Doctor wakes up. When he tries to leave, he finds that the TARDIS doors are jammed shut. The plants have been spraying his craft with sap, which has hardened into a shell and is cutting off the oxygen. He starts to suffocate. Jo, meanwhile, finds a spacecraft and explores inside. Two men show up, Taron and Vaber, and she tells them about the Doctor and the TARDIS. They tell her to hide in the spaceship while they go and tend to him.
Another man, Codal, joins them and warns of an approaching ‘patrol’. While waiting in the spaceship, something invisible breaks inside but doesn’t discover her. The men find the TARDIS and break through the shell, rescuing the Doctor. He recognizes that the men are, in fact, Thals and he tells them that he is the very same Doctor from their legends.
The Doctor is informed that he has been infected by a deadly fungus and must be cured with a spray the Thals have. Said fungus is spread when the plant life sprays sap. Indeed, back at the spaceship, a fungal growth has appeared on Jo’s hand and she is suffering maladies. The Thals tell the Doctor they’re on Spiridon, inhabited by invisible creatures. They make their way back to the spaceship, but come across something invisible and immobile. Using some special spray, they are able to reveal what the invisible thing is. It’s a Dalek.
At the very least, the Dalek is dead. They realize that the Daleks are trying to learn the ability of invisibility from the local Spiridons. The Doctor learns that the Spiridons are enslaved, but there are only about 12 Daleks on the planet. Continuing along, a Spiridon patrol intercepts them and Codal is captured while trying to make a diversion. They return to the spaceship, but see that the Daleks have gotten there first and are about to destroy it. The Doctor leaps out and begs for them to stop, but they completely destroy it anyway.
The Doctor is taken back to the Dalek base and imprisoned along with Codal. Unable to escape, he tries to rig up a device to disorient the Daleks at close range. Jo, however, is not dead. Before the Daleks had arrived, a Spiridon had found her passed out in the spaceship and carried her away. He cures her fungal infection and tell her what happened to the Doctor. The Spiridon’s name is Wester. Meanwhile, the other Thals retrieve explosives they had hidden earlier. They are interrupted as another Thal spaceship lands, bringing three more Thals. Latep and Marat, two more males, and a woman named Rebec who is Taron’s lover. She informs Vaber and Taron of what they have learned; there are not 12 Daleks on the planet, but ten thousand!
Jo and Wester watch the enslaved Spiridons enter the base. They are wearing purple fur coats to protect them from the cold. Jo decides to sneak into the base by hiding in a supply crate. Meanwhile, the Doctor and Codal use his device to escape their cell, and meet up with Taron, Marat and Rebec. The Thals had been trying to sneak in through the ventilation shafts, but encountered danger. The planet contains a core of molten ice, and an ice eruption flooded the shafts and nearly engulfed them. The Doctor manages to rescue them and then they all flee from approaching Daleks.
Marat is killed while trying to buy them time. Unfortunately, he was carrying a map of where the explosives are hidden which the Daleks now have. Jo, now on the base, overhears orders to destroy the explosives and sneaks out to follow the patrol. The Doctor and the Thals end up trapped in a room with a large refrigeration unit, and they see the army of ten thousand Daleks through a window. With nowhere else to go, they rig up a makeshift hot air balloon and rise up through a ventilation shaft.
A Dalek uses a gravitational disk to chase them, but they escape in time. Waiting at the top are Vaber and Latep, who drop a rock on the pursuing Dalek. A few moments later, Jo happens across them. She and the Doctor are overjoyed to see each other, having thought the other was dead. Jo has also managed to retrieve two of the explosive devices.
Night is approaching. Though tropical and humid during the day, Spiridon is subject to sub-zero temperatures at night. The group travel to the Plain of Stones, an area full of rocks that absorb sunlight and discharge it at night, to wait until day. Vaber and Taron start arguing, having been at odds for a while about whether to take immediate action or not. Their fight is broken up, but Vaber steals the two bombs and runs away during the night. Taron and Codal run to find him. They knock out Spiridons and steal their coats as a disguise when they find Vaber is kidnapped by the Daleks. They try to interrogate him and then kill him when he refuses, but Taron and Codal are able to retrieve the bombs in the confusion.
Back with the group on the plain, Wester shows up. He tells them that the Daleks have developed a bacterial weapon that will wipe out all life on the entire planet, aside from those who are immunized. He leaves to try and buy them time, and then the Dalek patrol catches up to them. The group lure them over to a pool of molten ice and manage to toss them inside. This kills them instantly and gives the Doctor an idea.
They head off to the base with Taron, Codal and the Doctor dressing as Spiridons, while Rebec hides in an empty Dalek casing. Jo goes with Latep to try and enter through the ventilation shaft. Once inside, the Doctor’s group watch as the some of the Daleks are immunized, seeing that Wester is with them. While they are distracted, Wester dives forward and released the bacteria into the room. Wester is killed, but the room must remain sealed or many of the Daleks will be killed as well. Thus, the bacterial threat is eliminated.
However, the rest of the group is outed when a Dalek spies their not-invisible feet. They flee, returning to the cooling chamber and barricading the entrance. The Doctor discovers a crevice in the ice walls of the underground chamber containing the Dalek army and believes that planting a bomb there will destroy the whole cavern. However, as they work, the refrigeration unit is turned off and the Daleks start coming to life. Jo and Latep arrive and use their bomb to destroy the Daleks breaking through the barricade.
With everyone together, the Doctor detonates his bomb. At first nothing happens, but then the walls break down and molten ice starts flooding in. All of the Daleks are completely consumed in the ice, which spreads through the base and affects all but the three in charge. This includes the Dalek Supreme, who had recently arrived. Once back on the surface, the Thals decide to steal the Dalek Supreme’s ship so they can return safely to Skaro. Latep has fallen in love with Jo and asks her to come with him, but she declines and asks the Doctor to be taken back home.
Thoughts: The Daleks are back in a big, long adventure. The Thals are also back, and it’s cool to see them again! This was a very good serial with an interesting setting and exciting action.
The serial was rather similar to the first Dalek story, but with a lot of changes and improvements. The Thals were all well defined characters, even though they looked quite similar in design and were hard to tell apart. They all felt like individual characters and I enjoyed their presence on screen.
The Daleks were just as intimidating and vicious as ever. For reasons that I’m not completely clear on, all but the Dalek Supreme were coloured black. This was unusual, but it was kind of neat to see them all in a dark, intimidating colour. The Dalek props were able to move through rougher terrain this time, making them more of a threat.
One thing stands out to us as not making any sense. When the group push two Daleks into a small pool of molten ice, the Daleks are killed instantly. However, when the ten thousand Daleks are engulfed in a huge flow of molten ice, everyone says that they have just been frozen and can be 'dug out’. This is in fact what the remaining Daleks plan to do. This is a big contradiction and a big plot hole.