u/Devil_s_Advocate_

Harry and Daphne are happily married, with 2 children, when they find out one of them have a marriage contract (could be either of them) they will be forced to fulfil. Now, the Potters are desperate to protect their marriage and family from the claws of evil marriage contracts. Even if it means threatening and assassinating a few influential people.

Oh, and maybe they start a war with the goblins.

Harry's Deathly Hallows come handly.