This one is an art episode, but also a murder episode and also a madness episode. Artist Richard Dadd's life story is quite sad, but his art remained consistently good, even at the lowest points in his life.
Research:

Behind the Scenes Minis: Stairs and Trains
29:25

Elizabeth Blackwell's Curious Herbal
34:51

The Many Meanings of the Bunker Hill Monument
45:48