The Doctor programs himself with the personality traits of famous historical figures.
This is an okay episode with an interesting theme, but I struggle with certain aspects of it.
The Doctor having a Jekyll and Hyde experience is a good concept, but the inclusion of the historical figures for me does not work and there are some other aspects of the plot that are too silly for me.
It includes another Star Trek romance that does not work very well. However, it also feels like certain scenes related to this, such as Kes and Janeway's dialogue exchange are laying the foundations for future episodes. Thankfully though, the love scenes are not a very prominent part of the story.
Robert Picardo is a brilliant actor and his casting was one of the biggest positives in Voyager. His performance in Darkling is as committed and charismatic as ever, but the voice he uses and leering facial expression when in 'Hyde mode' I find irritating and repetitive after a short period of time.
The production values are strong, especially the atmosphere created in certain scenes and one visual effect involving the transporter is very cool.