What if someone you loved faded away in front of you, and you were left wondering whether the person you knew ever really existed at all? Meet Victoria Johnson and Derek Draeler, two everyday people for whom a chance meeting grows into the promise of a wonderful new life together. When Derek suffers a severe reaction to a prescription antidepressant, Victoria watches as the personality of the man she loves twists into something she can no longer recognize. As Derek's condition worsens, Victoria sifts back through the tiniest details of their relationship and the riddles of his past for any clue that might separate his withdrawal symptoms from the man Derek may truly have been all along.