Discontented middle-aged doctor Alain Massoulier has received a life-changing letter - thirty-three years too late. Lost in the Paris postal system for decades, it offers a recording contract to Alain's old band The Holograms, which split up long ago.
Now, overcome by nostalgia, Alain decides to track down his old bandmates - including the alluring singer he secretly loved. But in a world where everything and everyone has changed, where will his quest take him?
