Ghost Cat: Thelma's Dilemma

When Jim and Sarah Gaunter hear of the death of Gertie, their elderly former neighbor in Tennessee, they make the trip back from Michigan to attend the funeral. Jim isn't as anxious to go as Sarah and their two daughters, thirteen year old Riley and six year old Susanna just like riding in the car. When Gertie's adopted son tells them that Gertie wanted them to have a rather large, heavy trunk, Jim loads it on top the van and heads for home. The weather is bad and an ice storm is making the I-75 expressway very slippery. When Jim has to make a quick jerk to the right to avoid being smashed by a truck, the trunk falls off of the roof and onto the side of the expressway. They would rather just leave it and continue on their way home, but they realize that someone else could hit it and cause a very big accident. They circle back and retrieve the trunk which has damage and continue home. The next day Sarah hears something coming from the trunk that they had transferred to the garage and forgotten about. Who or what is in that trunk?