While the Brizan community is reunited on the beach for its annual surfing party, a strange cloud is falling abruptly on the ocean. And when it leaves, astonishingly, there are no surfers on the water, only their empty and abandoned planks are repelled by the waves onto the shore. Five hours later: Lena, Max, Thomas, Mathieu, and the others reappear miraculously, safe and sound, but without any memory of what happened to them.