I think I've written about Stones of Blood, a Doctor Who serial from 1978, a couple times now. I love the gloomy Cornwall atmosphere mixed with some mildly absurd comedy. The Wikipedia entry for the serial quotes one reviewer as saying the first two episodes have a Hammeresque quality that the final two episodes lack, presumably because they focus more on futuristic sets, lingo, and comedy. It seems like a lot of Doctor Who serials follow that trajectory, though, starting with weird atmosphere and ending with technical explanations and solutions; The Mind Robber, to a certain extent The Horror of Fang Rock and The Web of Fear. It's nice when a serial manages to hold to the atmosphere all the way through but The Stones of Blood is still a delight.
I actually fell asleep halfway through Part I this time and slowly woke up in the middle of Part II to see the dark shape of Tom Baker with K-9 wandering across the garden of an old manor house.
The disorientation was kind of a lovely way to experience the episode and I didn't quite know what was happening when the Doctor entered a wrecked drawing room with wood panelling, littered with twisted corpses.
Another thing I love about this serial is Beatrix Lehmann as Professor Rumford, there investigating the strange standing stones at Boscombe Moor. This was to be her final television role--she passed away the following year--and she's in top form in her dialogue with Tom Baker, switching between incredulity, wit, bewilderment, and erudition.
It's also nice to see Mary Tamm again. I'm more of a Romana II fan but Tamm has a kind of serenity in her snootiness that plays off Baker really well.