An American traveling in Europe suddenly disappears, and his daughter, married to an eminent scientist, receives a letter asking her to go to Antwerp, which she does with her young son. Both are about to disappear. OSS 117 is asked by his superiors to solve these mysterious disappearances.

Delphine and Solange are two sisters living in Rochefort. Delphine is a dancing teacher and Solange composes and teaches the piano. Maxence is a poetand a painter. He is doing his military service. Simon owns a music shop, he left Paris one month ago to come back where he fell in love 10 years ago. They are looking for love, looking for each other, without being aware that their ideal partner is very close...