Sunny Boy: Arthur Guérin-Boëri is suffocating in his local swimming pool. His swim lane has become a dead end. The French athlete, multiple world champion in dynamic apnea, decides to leave the warmth of his pool and plunge into the frozen waters of a Finnish lake to set a new record. His journey then led him to immerse himself almost naked under a block of ice, in an attempt to set a new record in the icy waters of a Canadian lake. In his quest for legitimacy, which brings him close to death on several occasions, Arthur ends up finding himself.