Self-help writer Lorna Sisco (Nicki Whelan) has recently remarried and moved herself and teenage son Mark (Parker Mack) into her new husband's (Jesse Hutch) home. At the family's 4th of July pool party, Mark meets his seductive teenage neighbor Mallory (Ashley Rickards), who quickly insinuates herself into the young man's life. Lorna soon finds Mark breaking up with his current girlfriend, giving up tennis, and partaking in more reckless behavior. She attempts to get her son's life back on track, but Mallory's influence over Mark causes him to push his mother even further away. After catching Mark and Mallory drinking and stripping by the pool one night, Lorna forbids Mallory from seeing her son. This only strengthens Mallory's resolve and she's soon disrupting Lorna's career and new marriage. Lorna desperately searches for answers and digs into Mallory's cryptic past, only to discover they share a horrible connection and that Mallory intends on destroying everything Lorna loves.