1)We open a new era for Doctor Who with a new title sequence and this new-fangled thing called color filming. Those of you who are old enough may well remember back in the day how much noise was made about TV shows being shown "in living color", when color TV was first introduced.. Ironically, we were the last people in the United States to get a color set (the Old Man thought they were radioactive or something, I guess), so I still saw most of these in black-and-white the first time I watched them. The first story of the Pertwee was written by my favorite Doctor Who writer, Robert Holmes, and introduced the Autons, who would return to be-devil the Third, Ninth and Eleventh Doctors. The Autons are reasonably effective baddies in this - the scene where they break out of the shop windows and start slaughtering people was quite creepy, which is no sdoubt why our Russell ripped it off for "Rose"..
2)Pertwee does reasonably well in this, there are times when you can really feel that this is the Troughton Doctor with a new face. Obviously we can't see "Power of the Daleks", so this is in effect the first "The Doctor is all mssed up post-regeneration" story that we can see. This kind of story became common practice over the years, until for me at least, it became a bit wearisome. At least with "Rose", we were spared this, although the nerdboy in me is still slightly peeved that we never got to see the Eighth Doctor's regeneration into the Ninth. We also see here the beginning of the Doctor's occasional haibt of stealing clothes form a hospital after he's regenerated. They do contrive to keep us from seeing Pertwee's face for awhile, what with him going plop out of the TARDIS and then him covering up with a hospital blanket for most of Episode 1.
3)Interesting that the Tme Lords let him keep the TARDIS, considering that he stole the thing in the first place.
4)We get the set-up of UNIT, what with the re-introduction of the Brigadier and the introduction of Liz Shaw, "an expert on meteorites - degrees in medicine, physics and a dozen other subjects." Always liked Liz as a character, and I thought that Caroline John had a good rapport with Pertwee - frankly, a little of Katy Manning's wackiness went a long way for me.
Not my favorite Holmes story, but still quite good. "Introducing a new Doctor" stories are always tricky, but this one does OK. I think that one of the strengths of the show was that its format made it uniquely able to change with the times, and it certainly did so successfully here.
[Part of list of Doctor Who episodes here.]
I'm watching "Spearhead" on blu-ray now. It's beautiful. It looks like a Doctor Who feature film was made by Hammer Studios in the early 70s. I almost wish it had an option of watching in the "omnibus" format.
There was some kind of strike, and they were forced to do the entire thing on location-- and on FILM! The only downside-- at least in the version I've seen-- is the sound is hollow. I'm not sure if that's something that could be fixed, but they can work miracles with sound these days.
The Philly station that got Pertwee's 1st 3 seasons when they went into syndication in the mid-70's SKIPPED this story. (Grrrrrrrrr) So I never got to see it until around 1985, when it came over with the 2nd set of Pertwees. (After "THE FIVE DOCTORS", about half the Pertwees were added to the PBS package. But this one was among the missing.) Everything after "DAY OF THE DALEKS" was also skipped by my local station in the 70's. The very point where Pertwee's Doctor was beginning to lighten up and become nicer...
I love the scene where Pertwee arrives at UNIT HQ and introduces himself. It's funny how he immediately hits it off with Liz Shaw, while keeping the Brigadier at a distance, as he doesn't really want to be stuck on Earth. I forget if I'd seen the few Troughton stories that were available before or after this, but at some point I realized that Pertwee went thru this entire story "doing" Patrick Troughton. He'd been hired specifically because of his comedy skills, but once Barry Letts took over (beginning with "THE SILURIANS") the entire tone of the show changed drastically.
If I recall the reason given in the books was that the Time Lord's had decided to at least partially abandon the non-interference policy and use the Dr. as an agent at times. I remember in the episode where the Dr. goes to Galifrey the chief detective investigating is listening to a bio of him and there is mention of a Celestial Intervention Agency, but I got the impression that it was a covert group.
I think it makes sense because as I recall during the Pertwee years the Time Lords did send him here and there at times.