A major plot strand in Season 1 was dropped abruptly and apparently never resumed. It was kind of reminiscent of all the stuff about Gerard's pirate ship, the Java Queen, and her matey zombie crew--a major plot point in Summer 1970 that was practically nonexistent once they started with 1840.
Of the regulars, I don't think they ever bothered to integrate Dorian Gray at all into the plotline. Too bad because Reeve Carney is really very good and was a screen presence who grew on me (initially, I just couldn't accept him as Oscar Wilde's Dorian, but this version of the character had his own groove going on).
G.