Adrian Marks is introduced to Veronica as Aurora's gay best friend by her father and step-mother. During her visit to Adrian during the Neptune spring break season, Aurora and Adrian visit the party hosted by the Gutierrez cousins, the same party that Hayley Dewalt went missing from around a week ago.
It is on Aurora's visit to Adrian that she goes missing. Upon Veronica's finding of Hayley's body and the realization that the two incidents must be separate, Adrian confesses that Aurora told him that she was really in town to see a guy, and that they were going to run off together and go "off the grid," which is why no one could reach her.
In the end, Veronica discovers that Tanner was forced by his associate, Duane Shepard (alias Lee Jackson), to capitalize upon the disappearance of Hayley Dewalt by faking his daughter's abduction. Their plan was to create a fake ransom demand for both Hayley and Aurora's return, taking the reward money (funded through a hotline from Trish Turley's talk show) as ransom and disappearing to Bermuda. Their plan is foiled by a phone call from the real Lee Jackson, who is a woman working for the Meridian Group specializing in ransoms and kidnapping. She quickly unravels the scheme, which ended up concluding in Aurora trying to double-cross her father and his partner.
Aurora had Adrian, her secret boyfriend, assault Duane in an alley near the Neptune Grand with one of her brother's maracas, stealing the ransom money from Duane and framing her father for his attack. It is revealed that Aurora has planned this secretly since the inception of the plan, and had brought in Adrian, who had also feigned being gay for years so that the two could have a sexual relationship under her parents' roof. Adrian and Aurora intended to take the money and get away, but are stopped by Veronica and Keith.
Adrian is arrested with Aurora and Tanner, with Lianne facing the possibility of being charged as an accessory to the crime.