Dean pressures Sam into traveling to Cicero, Indiana, so Dean can visit an old flame named Lisa (CINDY SAMPSON), with whom he had a tryst nine years ago. Dean is stunned to meet not only Lisa but also her 8-year- old son, Ben (NICHOLAS ELIAS), who bears a striking resemblance to Dean. When Ben goes missing, Sam and Dean discover that a changeling -- a demonic parasite -- is snatching kids from the small town and taking on their form. Meanwhile, a woman named Ruby (recurring guest star KATIE CASSIDY) contacts Sam and reveals some startling information about his mother.