It tells of the events before the film, in which monster hunter Gabriel Van Helsing travels to London to investigate a series of horrific, and decidedly supernatural murders, being committed by the mad scientist Dr. Jekyll, in the form of his evil alter-ego, Mr. Hyde.

Hugh Jackmanas Gabriel Van Helsing (voice)
Robbie Coltraneas Mr. Hyde (voice)
David Wenhamas Carl (voice)
Grey DeLisleas First Victim (voice)
Dwight Schultzas Dr. Jekyll (voice)
John DiMaggioas Coachman (voice)
Scott Mosensonas Palastwache (voice)
Alun Armstrongas Cardinal Jinetta (voice)
Roger L. Jacksonas Gentleman (voice)
Julia Fletcheras Lady (voice)