The Exploding Planet (Galaxy 4 Episode 4)

The one where the planet explodes...

Pretty much the only thing of any note that happens in The Exploding Planet is that the planet explodes. I'm not even being glib here. Most of the 25 minutes is spent hooking up the Rill ship to the TARDIS with a very long cable, and characters flitting between various locations. Maaga and the Drahvins fail spectacularly to capture the Rill ship (although they do manage to disable one Chumbley using an iron bar), while Steven spends most of his time arguing a lost cause with the Rill leader.

It's B-movie sci-fi by numbers, and brings to an end a story which comes nowhere near fulfilling its potential, but is still oddly engaging, largely thanks to its visual and aural attributes (eg, the Rills, the Chumbleys, the Drahvins and the accompanying sound effects).

Air Lock (Galaxy 4 Episode 3)

The one where we finally get to see the hideous Rills...

Galaxy 4 is known to be Peter Purves's least favourite Doctor Who story, and it's easy to see why. Steven has very little to do, stranded alone with the Drahvins for the entirety of Air Lock, either asleep or getting himself into ridiculously stupid situations. He manages to knock out his drowsy Drahvin guard and steal her gun (and by the way, what is that odd ripping noise when Steven stands up? Is it his trousers splitting?), but he then gets trapped in the ship's air lock (hence the episode's title, everyone!) with no way out. Maaga gives him her callous ultimatum - either stay in the air lock and die of oxygen starvation, go outside the ship to be killed by the Chumbley, or lay down his gun and return inside, to be prisoner of the Drahvins once more. Through all of this, Peter Purves, with his messed-up coiffure, probably looks the most handsome/ vulnerable that he ever did.

I've said it before and I'll say it again, but Steven Taylor is supposed to be an ace space pilot from the future. He's supposed to be a man of action, a hero figure who has the brains and brawn to get himself out of sticky situations like this. He's Dan Dare, he's Flash Gordon, he's Buck Rogers! But all Steven can do is resign himself to his pathetic end, his pride being the only thing stopping him from falling back into the Drahvins' hands. I'm pretty sure he could have shot at that Chumbley with his gun and made an effective escape before it recovered, but he doesn't even try. Instead, he slips gently to the ground as the oxygen is pumped out of the air lock. What an ignominious end for such a supposedly dynamic character.

Trap of Steel (Galaxy 4 Episode 2)

The one where Maaga's got our heroes over a barrel...

What trap of steel? Does the title of this episode refer to the Drahvins' spaceship? I suppose it could, because from first Vicki's point of view, and then Steven's, they are prisoners there, but the Doctor's mild obsession with the material from which the ship is built rather undermines it as a formidable structure. "My ship's not made of tin like this old trash," he barks. "Seems if I coughed too loudly the whole thing'd fall to pieces!" So, not a very good trap of steel then?

Not an awful lot happens in this episode, but that doesn't make it less enjoyable. Galaxy 4 is often maligned for being somewhat unsophisticated in its themes, but the story is really rather engaging. You've got some interesting aliens with a truly merciless leader, some cutesy robots, some apparently ugly monsters, and two opposing factions in a race against time before a big bang. There's more going on in Galaxy 4 than your average episode of Lost in Space (a series which Doctor Who has arguably begun to resemble by this point, despite the US show only having premiered in America the same week as Four Hundred Dawns).

Four Hundred Dawns (Galaxy 4 Episode 1)

The one where the TARDIS crew is taken prisoner by space vixens...

And so here we are at the top of Season 3, more than 80 episodes after the series first launched in November 1963. In the six weeks that Doctor Who was off-air between seasons, the programme's slot was filled with another of my favourite things, classic comedy from Laurel and Hardy (The Music Box (1932), Hog Wild (1930), Dirty Work (1933), Towed in the Hole (1932) and Oliver the Eighth (1934)), plus the first in a new run of The Dick Van Dyke Show. If only the BBC would show those classic Stan and Ollie shorts on Saturdays again, but that's for another time entirely...

Four Hundred Dawns also marks the start of a prolonged period of missing episodes which pretty much lasts for the next three years. From the entirety of Seasons 1 and 2, just 11 episodes are missing, whereas Season 3 alone has 27 episodes missing from a total of 45 (60%). Doctor Who between 1965-68 is something of a Swiss cheese experience, with many stories either completely missing or partially missing. Of the 26 serials broadcast in Seasons 3, 4 and 5 (1965-68), only five exist in full (19%). Some have been patched up using animation, but it's just not the same. And so my journey through this frustrating period begins, on audio recorded during the live broadcast by David Holman, plus almost six minutes of footage which survives thanks to the 1977 Whose Doctor Who documentary.