Case Study Legal Writing: Winston and Edward

Please write your answer in the IRAC format.
Edward is a licensed physician. One of his patients was an elderly man named Winston. Edward treated Winston for Alzheimer's disease, but since he believed he was destitute, he never charged him for his medical services.
In late Fall Winston went to see Edward for a routine checkup and Winston said to Edward, "I want to pay you back for all you have done for me over the years. If you will care for me for the rest of my life, I will give you my office building. I'm frightened because I have no heirs and you are the only one who cares for me. I need to know now that I can depend on you." Edward doubted that Winston owned any office building, but said nothing in response and just completed his examination of Winston and gave him some medication.
Since Winston made the statement two years went by. Winston's health worsened and Edward continued to treat him. Edward forgot about Winston's statement regarding the office building.
After five years of treating Winston, Edward learned that Winston was indeed the owner of the office building. Edward, remembering of what Winston had told him, immediately wrote a note to Winston stating, I accept your offer and promise to provide you with all the medical services that you may need for the rest of your life." Edward signed the note, put it into a stamped envelope addressed to Winston, and placed the envelope outside his front door for the postman to pick up when he arrived to deliver the next day's mail.
Winston died in his sleep that night. The postman picked up Edward's letter the following morning and it was delivered to Winston's home a day later. The services rendered by Edward to Winston over the last seven years were worth several thousand dollars; the office building is worth a million dollars.
Does Edward have an enforceable contract for the transfer of the office building? Discuss.
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