X enters into a contract with Y to deliver a rare painting by Bansky to Y in exchange for $100,000. After delivery, X and Y both discover the painting is a fake. Y cannot get rescission because this is a unilateral mistake of fact. Y cannot get rescission because this is a bilateral mistake of fact. Y can sue for, and receive, rescission, because this is a unilateral mistake of fact. Y can sue for, and receive, rescission, because this is a bilateral mistake of fact.