Who could have imagined that under the guise of the young midshipman Kent, brave, efficient and decisive, his sister Sally entered the ship? No one except Lieutenant David Colliar, who unraveled her secret from the first minute. He directly makes this clear to Sally and yet, taking pity on the sea-loving girl, he hesitates to expel her from the frigate. However, the tension grows every day - David falls more and more in love with Sally, and every minute a scandal can break out that will cover her with indelible shame and destroy him career...