After spending a year taking care of her grandmother in Florida, seventeen-year-old Tessa Daniels travels to California to visit her father and two brothers at their new house, but only on the condition that it's only for the summer. She's up to the idea - until the next door neighbor begins to take notice in her. His name is Alex Bennett. He's six-foot-two, and he's the perfect kind of muscular, but most importantly, he's cute. That, however, is precisely what prompts her to stay away from him. She sees no need in getting involved in a relationship just to have her heart broken and shattered to pieces, like she witnessed when her parents had a major downfall in their marriage. All Tessa wanted was an innocent trip to California. What she got was a journey filled with smiles, laughter, heartbreak, and love. And to think - it could all happen Once Upon a Summer.