Everything should have been perfect. Maven and Beulah "Cookie" Simmons are headed to a family reunion, but when Mama gets an unsettling call from her sister, they decide to delay those plans and detour to her house. What is supposed to be a simple visit turns into much more when Mama and Cookie discover a body and Mama's sister is accused of murder. With suspects around every corner, cryptic files, a creepy town, and secrets hidden in the trees, Mama and Cookie will have to work overtime to solve this case. Will Mama and Cookie find the murderer in time to make it to the family reunion and sing Christmas songs? Or is it (Christmas) lights out for them?