Back โover here,โ the Fringe Division investigates a bizarre phenomenon when 15 people up and down the Eastern Seaboard, all suffer retrograde amnesia from listening to their shortwave radios on the same frequency. Much to Walterโs dismay, Peter presses on with piecing together the mass destruction device. Just as alternate Olivia and Peterโs chemistry deepens, the anticipation of Oliviaโs return escalates.