Steven Moffat has written a second series, but the BBC have so far declined any interest in making it.
James Nesbitt was cast because he could play Hyde straight to the edge and then pull back from it in an instant.
Jackman's sons are named "Harry" and "Eddie", a reference to Henry Jekyll and Edward Hyde from the Stevenson novel.
Each episode was shot in 12 days.
The Klein and Utterson Institute is a reference to Robert Louis Stevenson's narrator from "The Strange Case of Dr. Jekyll and Mr. Hyde," Mr. Utterson.