It's the first day of their sophomore year at Smallville High, and Chloe Sullivan is back from Metropolis. Gabe Sullivan is now part of LexCorp as he contributed heavily to Lex's buy out and hence, they get to stay in Smallville. Chloe interned at the Daily Planet during the summer from the internship she won in Obscura, and despite Clark promising to email and visit, he did neither. Chloe tells him there are no stories about the Planet to tell and that she met some guy who made her forget about Smallville "for three whole months."
Chloe, Clark, Pete, and Lana are in the same biology/sex-ed class. Chloe notices Clark checking out their teacher and laughs at him; about thirty seconds later after continuing to ogle their teacher, Clark accidentally triggers his heat vision for the first time.
Clark spots Chloe at Lex's wedding later and strikes up a conversation with her; he tells her he's been looking for her and she retorts that she's "not that hard to find." They continue having a conversation about pheromones which preps the digging later in the episode and Chloe tells Clark that it boils down to chemistry. Chloe tells Clark that "love is rarely, if ever, logical."