It's easy to understand why the story is regarded as very good but not often given the label of "classic". It is, after all, a two-part nugget in between two giants ("The Visitation" and "Earthshock"). However, the real appeal of "Black Orchid" comes not from any grandiose ideas but rather from it's subtlety, attention to detail, and novel approach.

Firstly, "Black Orchid" is a completely historical story (something that had not been done since "The Highlanders" in 1966). The ONLY science fiction element in the story is the TARDIS. This was a wonderful breath of fresh air after experiencing nothing but year after year of monster and space baddie stories. It also gave the BBC a chance to do what it does best.....period drama. The plot almost resembles an Agatha Christie whodunit novel complete with a series of murders in a post-Victorian estate with secret passages and dark family secrets. As a result, the story has very high production values, from the authentic railway station to the Cranleigh Estate to the costumes at the fancy dress party.

Secondly, the guest cast is superb. Moray Watson as Sir Robert comes off as my personal favorite because he mixes compassion and logic into his character rather than being just one of those dumb police officers that are present in so many other stories making wild accusations at the Doctor ("Nightmare of Eden" comes to mind). Michael Cochrane and Barbara Murray are also quite good as Lord and Lady Cranleigh but it is Sarah Sutton who steals the show playing the role of Anne. Watching the same actress play both the animated, energetic Anne and the reserved, soft-spoken Nyssa made me realize just how good an actress Sarah Sutton really is.

Thirdly, the main four regulars have some wonderful moments. The best character development for any regular in Doctor Who comes during leisure scenes, and "Black Orchid" allows everyone their chance. We find out that the Doctor always wanted to drive a railway car as a boy, is an excellent fast bowler, and likes to sing in the shower. Tegan's softer side comes through in several great scenes as she shows Nyssa how to dance the Charleston and innocently flirts with Sir Robert at the fancy dress party. Adric and Nyssa have some great moments together (I love the shrug they give each other after hearing all that Cricket terminology), but their best lines come at the dance when Nyssa has to practically order Adric to dance with her: "Not them you idiot, each other. Go on, ask me!". And of course, there's the wonderful scene at the buffet where Matthew Waterhouse gives his best delivery ever. Sarah Sutton walks up, looks at Adric's plate and says: "Is that seconds? You pig!" to which he replies: "YOU could only be Nyssa."

Speaking of great lines, "Black Orchid" is full of them: "A splendid performance, worthy of the Master," (Peter Davison's look is priceless); "Why didn't I leave after the cricket?"; and my all-time favorite..... "You said he was a friend from Brazil, where the nuts come from," (a wonderful subtle reference to the comedy farce "Charlie's Aunt".....the script editor was bordering on genius).

Finally, Peter Davison's greatest characteristics shine through during the climax of the story. Having tried time and again to be polite to his hosts, the Doctor, seeing Nyssa in danger, finally loses patience with Lady Cranleigh's lack of cooperation and delivers a great line: ".....and what will he do when he discovers he has the wrong girl!" Finally, resolving the situation through a gentle plea for George to release Nyssa, we are reminded that the 5th Doctor's strongest quality is his sensitivity.