But with the word the time will bring on summer,
When briars shall have leaves as well as thorns
And be as sharp as sweet.

Doctor's daughter Helena cures the king when all had given him up for dead, and in reward he promises her the hand of any of the gentlemen at his court. She chooses her childhood companion Bertram of Rossillion - only for him to reject her and go off to war with his comrades in arms. The resourceful Helena tricks him into making her pregnant, and (so Shakespeare would have us believe) they live happily ever after.