Marvin Mower (MM) is a college student trying to earn a few extra bucks. Marvin mows yards on the side, and he cuts the lawn for Ursula Unhappy (UU). UU writes MM a document for his work. The document acknowledges MM performed work, and that UU owed MM $50. MM doesn't have time to get to the bank, so MM gives the document to Tommy Thirdparty (TT), who pays him $40 for it.

Predictably, before TT can try to recover $50, UU is unhappy with MM's work, and refuses to pay TT.

Keeping your "eye on the ball", discuss all the possible rights and responsibilities these three have to each other concerning the check and the yard.