What is the matter with Mr. Frank, the man who has moved into Sam and Roberts building? Why is he so nasty? Why does he use so much electricity? And why are those odd moans and groans coming from his apartment. Sam and Robert think they know the answer. Together they reread one of Sam's horror books. Just as they thought, there are an awful lot of similarities between Mr. Frank and the man in the story, too many to be just a coincidence. Could it be true? Is Frankenstein really living on the fourth floor of their building? Sam and Robert aren't sure but they're determined to find out!