Dean pressures Sam into visiting Cicero, Indiana, so he can visit an old flame named Lisa, he had a tryst with nine years ago. However, Dean is stunned when he meets not only Lisa again, but also her 8-year old son Ben, who bears a striking resemblance to him. However, Ben soon goes missing and Sam and Dean discover that a Changeling, a demonic parasite, is snatching kids from the small town and assuming their form. Meanwhile, Ruby makes contact with Sam and reveals some startling information about his mom.