Mention the name Terrence Dicks to your average Doctor Who fan, and you'll get one of two reactions - either gratitude for setting the tone very early on in the series, and for keeping the flame through his Target novelizations; or his relatively lackluster later work, which tends to be more continuity-driven than your average DC comic. But ultimately, the question needs to be asked - does his work hold up?
Let's just say he's good at crafting a story, but he's not quite ready for the 21st century.
First comes Inferno - OK, technically he was script editor, and the episode was written by Don Houghton, but Dicks' storytelling ability shines through. Although Season Seven started off with the classic Spearhead From Space, much of it consisted of seven episode stories. Inferno, far from being padded, actually manages to maintain its pace - part of it is the Dicks'-derived idea of a parallel earth (and who else out there thinks this is the same earth from 2006's Rise of the Cybermen/The Age of Steel? Oh, it's just me). Being able to play out the story to a horrible end - and then revisiting the "real" world - helps give this story slightly more narrative power.
However, in the supporting materials for this and other stories - especially when discussing Caroline John's departure - Dicks shows some tendency towards, well, old fogeydom. First, he rather sheepishly claims that they let her go because she was a "proper actress", which is, well, less overtly sexist and patronizing than Barry Letts' contention that you can't have a companion as clever as the Doctor. Of course, both he and Letts complain almost bitterly that "they wouldn't have done it that way" on another story...which is considered one of highest rated. Go figure.
Of course, it didn't stop Dicks from writing Horror of Fang Rock - originally, a substitute for a script which later became State of Decay, this is a pretty competent mixture of alien invasion, lighthouses, and Agatha Christie's And Then There Were None. It's not going to be spoken in the same breath as, say, Talons of Weng Chiang (and in Chicago, was known for an infamous interruption - thanks to Laura for posting the reminder), but there is a kind of cool, sharp symmetry to it, and there is a great documentary that shows Dicks has done more than Doctor Who.
He does redeem himself, in terms of portrayal of women, in how he handles Leela. Of course, we all know she's a savage woman from a strange planet, known more for wearing a one-piece leather bathing suit and killing people...but here, she spends most of the episode fully clothed, first in a typical Edwardian dress and then in a big bulky turtleneck. In addition, she's treated almost like a male character - although there are flashes of her "savageness", she is increasingly being seen as more competent, more independent...almost a complete carryover from the aforementioned Talons. Dicks, at the very least, shows some willingness to transcend his own attitudes.
In many ways, Terrence Dicks is like the William Shatner of Doctor Who writers - no matter what he does, he will always be linked to the show. The sad thing is, that title cuts both ways - he will always be linked - and be trapped - in the show's past.