Planet of the Daleks Episode Six

The one where the Dalek army goes into deep freeze...

As soon as the Daleks learn that aliens have infiltrated the city posing as Spiridons, they "instigate condition of maximum security", which I rather think they should have had all along. It also begs the question of how many different levels of security the Daleks recognise, because so far in this story it's been pretty lax. They also learn in this episode that the Doctor is one of the aliens, their "greatest enemy", but surely this should be no surprise to them seeing as the Master gave the Doctor to them on the Ogron planet in Frontier in Space? They should have guessed he'd be around somewhere.

Terry Nation really ramps up the jeopardy in this episode, and continues to steal from his back catalogue, including the moment when we're made to think Rebec has been exterminated inside the Dalek casing (there was a similar bluff in The Daleks). Nation dials it up to 11 by announcing that the Dalek Supreme is about to arrive on Spiridon. You can sense the panic among the Daleks when they hear that!

Planet of the Daleks Episode Five

The one where two Daleks are pushed into an ice pool...

I must say that I'm impressed that I haven't seen a single glimpse of the actors inside the Spiridon furs, which is quite an achievement. But I've also come to realise how ridiculous the Spiridons are, walking around wrapped up in their purple pelts. They're supposed to protect them from the cold, but it only gets cold on Spiridon at night-time; in the daytime, temperatures are apparently tropical. So we end up with a bunch of invisible people, who you can't tell are invisible, walking around like heliotrope Yetis. If you'd just turned on BBC1 in the middle of an episode you'd think the production team had literally used big purple throws to double as monsters... which they kind of have!

The thistle-coloured throws are essential apparatus for our heroes in this story, used to both blind an attacking Dalek (similar to the use of the Thal cape in The Daleks) and smuggle them inside pretending to be Spiridon slaves. When Taron pulls on his fur, he looks like a blond Jon Snow doing an impersonation of Liberace!

Planet of the Daleks Episode Four

The one where a Dalek chases the Doctor up a ventilation shaft...

The Daleks may not be able to construct their own hot air balloon, but they can follow our floating Thal pals up the ventilation shaft on one of their anti-gravitational discs! How cool is that? The disc itself is literally a black disc, and nothing like the hoverbouts which have populated Doctor Who spin-off fiction since they first appeared in the Cadet cigarette sweets stories of 1964. In fact, it's a real shame the hoverbouts (sometimes called transolar discs) never appeared in the classic TV series properly, only ever in comics, novels and audio stories.

In a nice nod to the scene in The Ambush where the Doctor and friends bung a heavy object down the lift shaft to stop the approaching Dalek, the Doctor and the Thals chuck a load of rocks down the ventilation shaft and send the anti-gravitational Dalek crashing back down to the bottom. All very satisfying!

Planet of the Daleks Episode Three

The one where Jo smuggles herself into the city...

This third, beautifully recolourised episode is less than the sum of its parts, because while it seems quite busy, by the end of it you realise that almost nothing has happened at all! But to be honest, it's done with such conviction and flair that it doesn't really matter. What Terry Nation wrote, and David Maloney realised, is perfectly entertaining, like one of those runaround Saturday morning serials where danger and jeopardy supersede plot.

The Thals, their number now boosted by the survivors of the crashed ship, decide to make their way into the city via the ventilating cooling tunnels. The only problem is that the tunnels are connected to an ice volcano, which spews molten ice in the same way a regular volcano would erupt lava. This is classic Nation, making part of the landscape an obstacle to be overcome (a strong element of the first Dalek serial, and The Keys of Marinus), but there are such things as ice volcanoes in real life, also referred to as cryovolcanoes, which erupt with cryomagma or cryolava.

Planet of the Daleks Episode Two

The one where the Doctor believes the Daleks have murdered Jo...

Once the entire Dalek has been thoroughly sprayed with the colour aerosol it becomes really obvious just how stumpy and short the Daleks are compared to the 6ft 2in Jon Pertwee! The Doctor towers over the Dalek, which has the effect of diminishing the Daleks' screen presence considerably. I remember back in 2010 the Doctor Who production team said that the newly designed Paradigm Daleks (yes, I dare speak their name!) now stood with their eyestalk on a level with the taller Eleventh Doctor. If only they'd thought to do something similar back in 1973!

The Doctor and the Thals talk of this dormant Dalek as if it's a robot, saying it's deactivated and that an alarm will go if they open the casing. But surely there's actually a living being in there, a little creature which we've seen plenty of times before and since. Isn't the fact there's a potentially deadly mutant Dalek inside a better reason not to lift the lid than the fact an alarm will go off?

Planet of the Daleks Episode One

The one where the TARDIS gets squirted with deadly alien plant sap...

It's surprising to get a reprise from the end of the last story, at the start of this new one. I expected it would just follow on, but actually it all feels like one long epic story, the longest since Season 3 (but with two different titles).

After calling the Time Lords on the telepathic telephone, the Doctor collapses, and Jo activates the completely incongruous MFI sliding bed and wardrobe combo which has miraculously appeared in the control room. It's flush, clean white lines may actually be more Intergalactic Ikea than the slightly shoddier MFI, but its very presence is startling. At least in the 1960s they used to walk through a door, or onto a different set, when they showed the recreation areas. The same happens when the Doctor uses the emergency oxygen supply later in the episode - the little white cabinet on wheels just happens to be there, inches away from where he stands!