As previously discussed, Hartnell wasn’t able to take part in the recording of this episode, so his handful of lines had to be farmed out.  This occurs when David steps up to dismantle the Daleks’ firebomb (this would have been the Doctor’s only contribution to the episode).  It’s presumably a sign of the times that no thought was given to the possibility of Susan becoming the bomb expert.  It would have been a good reminder that whilst she looked like a fifteen-year old girl she possessed experience which belied her appearance.  But no, it has to be the man who takes charge, while Susan hovers anxiously in the background.

There’s a first in The End of Tomorrow – it’s the first time that Doctor Who filmed in a quarry (and this was one of those rare times when the location was actually shown to be a quarry and not an alien planet!)  John’s Hole at Stone, Kent has this singular honour.  And how well do the Daleks work in the quarry?  Answer, not very well.  We see one trundle a short distance rather slowly, but otherwise they wisely stay immobile.

The unmistakable Nicholas Smith, sporting an unexpected Mummerset accent, pops up as Wells.  He racked up numerous credits during the 1960’s but he’ll always be best remembered as Mr Rumbold from Are You Being Served?

Terry Nation has often been accused of being little more than a hack writer, churning out formulaic scripts at great speed.  His very brief original description of the Daleks is used as an example of this, but it’s fair to say that there were other times when he took more of an interest in detailing how his creations should be visualised.  His description of the Robomen is a good case in point.

“They are dressed in black from head to foot, high-necked, very utilitarian garb made from rough cloth. There is no expression on the face. The eyes stare unblinking. Their movements are a a little stiff, but not over-emphasized. They seem to have a slight mechanical quality about them.  Their voices are very mechanical and slow, like a child deaf from birth learning to make sounds.”

Maybe one of the reasons why Nation didn’t spend too long on descriptive passages is that he knew his ideas might not be adopted.  With the Robomen, some of his concepts were taken on board, but it’s notable that Nation didn’t specify that they should wear what appears to be wastepaper baskets on their heads.  The movie managed something more sleeker, but the concept of miniaturisation doesn’t seem to have been considered here.

With the Doctor unconscious, Susan and David are exploring the sewers.  In Nation’s original draft, David mentions that people moved underground to avoid the plague.  Their descendants are still there, but they’re no longer quite human.  Having adapted to living in total darkness, their “hair is matted and shoulder length and, like the face, it is totally white. Only the eyes make black circles. They are larger than human eyes, bulging and dark like those of a night creature. Canine teeth project over the lower lip.”  Instead we see Susan tangle with a friendly alligator.  Oh well, it was cheaper I guess.

We catch a brief glimpse of the Slyther.  It’s the sort of thing that defies description and you have to be impressed at how seriously William Russell reacts to it.  Later on there would have been the temptation to send it up (goodness knows what would have happened had Tom Baker met it – something along the lines of The Creature from the Pit no doubt) but Russell is rock solid.  The bizarre sounds it makes are also memorable.

There can be few odder cliffhangers than the sight of the Slyther advancing on Ian and Larry whilst it slowly waves a portion of itself.  Richard Martin might not be Doctor Who’s most highly-rated director, but at least he wisely chose to keep this shot as a close-up.