One day, Yumi's friend finds a weird voice message on her cell phone. The voice sounds like hers but it ends in a bone chilling scream. The call apparently came from her own cell phone. It's dated three days into the future, it'd be easy enough to dismiss as a prank call were it not for that fact that three days later, at the exact same time and the exact same scream, the friend dies. The coincidences begin to pile up as the circle of cell phone death warnings widens. Until one day, Yum realises that she's also got one missed call.