Luna Light is a popular caterer. She is particularly known for cooking delicious comfort food that is also organic and locally-sourced. Luna enters into a valid contract with Bob and Bertha Bear to provide the food for a party of 50 guests for their 10th-anniversary party. Just before the party, Luna gets a request from her mother to please come help take care of her father for a week, at their home two hours away, because he is recovering from surgery. It is not an emergency, but Luna would like to help her parents. She asks the Bears if it is all right for her to assign her duties under the contract to Maisie Storm, another local caterer. The Bears agree to the assignment of contract. The anniversary dinner night comes, and Maisie supplies the same menu that Luna had approved with the Bears. The Bears paid Maisie as soon as she delivered the food. However, in the middle of the party, the Bears realized there was a key difference from the food they expected- Maisie does not use organic or locally-sourced foods. The contract had not mentioned the use of organic foods; however, the main reason that the Bears had chosen Luna was that she advertised, and was known for, only using organic food. The Bears contact I your law firm and want advice on whether Luna can still be held liable for the problems with the contract.

Based the Bear's assignment of the contract would Luna still be liable for the problems in the performance of the contract?  Additionally, provide at least one legal case, as part of explanation and analysis?