Le Bel Âge: At 18, Claire is torn between swim practice and the pangs of first love. The elderly and eccentric Maurice Reverdy takes her in in his big house, but the girl carefully avoids this faraway figure, who is none other than her grandfather. Proud, rebellious, solitary, they represent two generations that are simultaneously attracted to and repelled by one another. Their lives will intertwine, as one seeks out her future and the other is tormented by his past.