3. Dr. Jekyll/Mr. Hyde
Warner Bros. PicturesAs far as cautionary tales go, this one fits the time period and makes a hell of a lot of sense. The theme of our group of heroes all having dark secrets they keep from one another is recurrent in the series, from Dr. Frankenstein's creation to Chandler's apparent lycanthropy. Perhaps Dr. Jekyll could be bought in as a replacement for the late Van Helsing but be forced to keep his arrogant evil side a secret in fear that his new employers would dutifully exterminate him. Maybe even have him responsible for the as-yet unsolved Ripper-esque murders that Chandler seem to think he may have committed. We'd also ensure our Mr Hyde is unlike the usual portrayal, like the one in the picture above. In an unlikely comparison, think The Nutty Professor here: Hyde would actually be super smooth and socially adept with the ladies, but obviously a completely deranged nutcase underneath. Jekyll, in contrast, would be quiet, unassuming and maybe even a little less physically attractive. The balance of learned man and deranged psychopath would need a talented hand, especially as the actor would be essentially playing two parts. The man for the job is our eyes is Toby Kebbell, one of the most underrated actors on the planet. He could easily pull off both the timid nature of Jekyll and the cocksure swagger of Hyde.