Since his wife Josephine died, Sam lost his way. Abandoning the bar where he used to perform dazzling concerts, he spends his nights alone in the hotel room where he first met her. The concierge, George, his best friend and mischievous guardian angel, takes on to shaking Sam's world by messing with the hotel keys. One night, a distressed girl thus burst into Sam's shelter and locks herself in the bathroom.

Lulled by Sam's comforting voice, Pi, as fragile and mysterious as her name, suggests an odd seductive game: to meet again in this hotel room, to open up night after night through the bathroom door and to open it only when they'll be ready to love each other. Pi is the spark that Sam was waiting for to fire up his world and come back to life and on stage again.