Sue contracts to buy six cases of vintage Barrona Valley wine from Goodvines Winery for $1,200. The contract states that delivery is to be made at Sue's residence "on or before May 1, to be used for daughter's wedding reception on May 2." On May 1, Goodvines' warehouse and delivery van are struck by lightning, which cuts power to their offices and disables the electrical systems in the van. No wine is delivered that day, and because of the power outage Goodvines does not respond to Sue's phone calls and emails. On the morning of May 2, Sue buys wine of a higher-rated vintage from Happy Hill Winery for $1,500. That afternoon, just before the reception, Goodvines delivers the wine at Sue's residence. She refuses to accept the wine. Analyse Sue's claims under the law of Contract.