Gallathea is set in Lincolnshire, an English county under the curse of a Neptune from Roman mythology who demands that maidens be sacrificed to a sea monster. Diana's nymphs and Cupid roam the woods, and Venus, by turning a maiden into a boy, helps two sacrificial maidens who fall in love with each other.
In this play Lyly sought to cause "soft smiling, not loud laughing," to give "counsel mixed with wit" not "sport mingled with rudeness."