Walgreen Properties, Inc. (Walgreen) (defendant) leased property to United Properties Limited Company (UPL) (plaintiff). The lease agreement provided that the rent for the property was $44,640 per year and that the term expired on December 31, 1999. UPL had the option to extend the lease for three additional five-year periods. UPL spent over $1.2 million on capital improvements to the property and subleased portions of the property to other businesses. The sublease payments to UPL were $263,500 per year. Under the lease, UPL was required to give written notice of intent to renew by September 30, 1999. UPL forgot to give notice, and on November 8, 1999, Walgreen notified UPL that the option to renew had expired. UPL attempted to renew the following day by sending a written notice, but Walgreen refused to renew the lease. UPL sued Walgreen, seeking a declaratory judgment that the late renewal notice was effective. The trial court granted judgment to UPL, and Walgreen appealed to the New Mexico Court of Appeals.