Two-part stories are such an odd beast. In my childhood, it usually meant there would be a bonus omnibus episode of Doctor Who airing after the regular four-part omnibus episode on a Saturday night. Today, one might incorrectly compare the two-parters of yesteryear with the single, 45-minute episodes of the new series, but no new series episode would contain such scenes as the cricket sequence from Black Orchid.
What makes Black Orchid, the first two-part story since 1975, all the more odd is the fact that it's also the first "purely historical" story since The Highlanders finished its run in early 1967. (I use the term "purely historical" in quotes for reasons that I'll explain in Episode Two...). There have been many detractors of Black Orchid, not least of all the main cast in the commentary on the DVD release of the story. Personally, judging from Episode one, I think it's a nice bit of 1920s whimsy.
There's some neat sequences of The Doctor being brilliant and cricket (the whole thing is made worthwhile solely to see Peter Davison legitimately bowl someone out on camera), and it's nice to see the BBC's penchant for period drama extends to the 1920s, as the sets and costumes are uniformly brilliant.