This Lifetime movie begins with young Bart being bullied off of his school bus. The other kids laugh at him but his older brother Jorey stands up for him. They walk their separate ways and when he gets home he tries telling Chris (his "father" and his mother's brother) about it but Chris is preoccupied with a pile of past due bills. He's having money problems for some unknown reason. Inside, his mother Cathy is paying attention to a little girl whose mother is dying of cancer. She tells him that the girl needs them but he needs her more. Feeling unwanted, he goes to his tree house, where there are porn magazines and jars filled with insects. His older brother comes along and they explore the next door abandoned house--and soon find out that has been purchased by an old lady, Mrs. Foxworth, Corinne (Heather Graham). Of course, this is their grandmother, recently released from the mental institution. She offers Bart a job to help her around the house because the wants grandchildren. Eventually she tells him that she's his grandmother. But the one who messes with young Bart is Corinne's servant, who used to work for her father. He says he sees something in Bart, the same quality he saw in his great grandfather, and even gives him his diary. It's misogynistic--and Bart starts to quote for it. His personality changes even more after he gets an infection his arm and hallucinates about his long dead relative. "A man who feels is week", he quotes, and believes.
His mother adopts the little girl after her mother dies, which Bart doesn't like, and the older brother's German Shepherd is killed. It looks like Bart did it. Later, we find out why Chris is having financial problems--and it's because of his step-mother having found out that he and Cathy are really brother and sister. She's threatening to tell the authorities and have their children taken away. This freaks out Cathy, who begins putting together a room up in the attic, just like in the very first movie. This is in case someone tries to take the children, so she can hide them. Thankfully, it doesn't come to that. Eventually everything comes to a head--and we find out if Bart is really turning into a psychotic kid.
IF THERE BE THORNS is a good sequel, paralleling events from the first movie and showing some different aspects of the characters. The story is continued in SEEDS OF YESTERDAY...