Sun City is a city located in Arizona.
Melinda May's Stay
In the aftermath of the War Against the Inhumans, Melinda May decided to take some time away from S.H.I.E.L.D.. She went to see her father William in Sun City as he had had a car accident injuring her in the hip, and claimed that she had come to look after him. However, William knew that there was another deeper reason for her daughter to come to Sun City.
Later, Lance Hunter journeyed to Sun City in an attempt to convince Melinda to join him in an infiltration into HYDRA which Grant Ward was trying to rebuild. Although Melinda initially refused, Hunter let the door opened. After a conversation with her father, Melinda ultimately agreed to join Hunter in his endeavor and left Sun City to return on the field.