National City Bank loaned money to Reger Development, LLC, to fund development opportunities. Reger signed a promissory note that required the borrower to “pay this loan in full immediately upon Lender’s demand.” Later, National City asked to have some of the loan paid back. Reger—who was not in default—filed a suit against the bank, alleging breach. Was the note a demand instrument? Should the duty to act in good faith implied in every contract apply to a lender seeking payment on a demand note? Discuss. [Reger Development, LLC v. National City Bank, 592 F.3d 759 (7th Cir. 2010)]