When his tight-knit French family learns that homosexual eldest son Léo (Pierre Mignard) -- whom they love unconditionally -- is HIV-positive, they meet the challenge head-on while trying to shield youngest son Marcel (Yannis Lespert) from the harsh truth. But 11-year-old Marcel knows something is wrong after overhearing part of the devastating revelation and, on a road trip to Paris, he confronts Léo with his suspicions.