This is another in the series of new full audio stories featuring Tom Baker as the Fourth Doctor and Louise Jameson as Leela. I really enjoy the relation between the Doctor and Leela; their personalities have a good sync in these stories. The Doctor is still trying to teach Leela new things, so decides to take her to a museum - but, of course, that's not quite where they end up - or do they? Along the way, Leela learns about butterflies, and struggles with the concept of "Runny Science" (Renaissance).
Both Tom Baker and Louise Jameson are brilliant in this story; their characters are spot on, and their interaction with the other characters, particularly the sinister Harcourt, is great. The Doctor displays the required anger and disappointment, and horror at Harcourt's actions wonderfully; there is no loss to the listener from this story being solely audio - you really do get the "look and feel" of the story conveyed throughout.
It's an intricate yet intriguing story, but I really wish these new Fourth Doctor stories were longer than just two episodes on a single cd! I want more!