This adversary complaint was filed to object to the amount, validity, and extent of a secured claim held by an assignee of the original lender. On summary judgment, the plaintiff argued that one of the promissory notes at issue is unsecured and unenforceable because no agreements securing that note had been assigned to the claimant. The assignee argued that all of the loans made to the debtors were cross-collateralized, so it holds a beneficial security interest in instruments securing other loans even though no formal assignment of those security interests was made. The court denied summary judgment, holding that the original lender, which still holds the security interests in which the assignee is also claiming an interest, is a necessary party to the litigation.