The bet
Hardin runs with Steph's crowd and doesn't get along with his father, Ken, who is about to marry Landon's mother. He needles Tessa from their first meeting, but invites her to the lake, kisses her and slowly falls for her. At his father's wedding, he tells her why he's so angry: Ken drank, and the family paid a terrible price.
The secret comes out in a video: Hardin started it all as a dare from his friends. He swears he has changed, but Tessa leaves. In the end, he writes an essay declaring his love and waits for her at the lake.