Ty may be the guy who actually follows through and abducts Gemma, but at one time, Gemma had another stalker. Stalker number two was none other than the dubious Josh Holmes, who had a crush on Gemma in spite of the fact that she was clearly not interested.
As a matter of fact, Josh was part of Ty's investigation into Gemma's life, which means that he was stalking both her and her other stalker at the same time. Dude, that's simultaneously weird and really meta. "He liked you, you know," Ty tells Gemma. "I mean, really liked you. He told Anna how much he wanted you" (37.99). So, yeah. Weird.
Josh primarily figures into Gemma's recollection of the night he tried to attack her, and he's portrayed like the shadowy figure in a horror movie where a girl gets followed and then hacked to death. Gemma describes him at the party as "hovering at the edge of our group like some sort of bat" (46.39) and "in the shadows, just behind" (46.40) her. Shudder.
Eventually, when Gemma catches the hint that Anna and Ben want to do the no-pants dance and she should probably leave, Josh goes after her. This ends up being a bad move—in an epic battle of the Gemma Stalkers, Ty attacks him and drags him into the bushes when he tries to interrogate her about why she won't talk to him.
So, we know what you're thinking: This book already has one creepy guy—why do we need two? We don't know for sure, but we can take a pretty good guess. Ty tells Gemma after recounting his side of the story that "that was the moment […] The moment I first knew I wanted you … the moment I knew I had to bring you here" (46.70). Not only does Ty want to save Gemma from the monotony of city life, he also wants to prevent her from its dangers. With just him and her and no one else for miles, he'll finally be able to protect her from threats like Josh.