What's really going on in apartment 405? For Erin, it looked like this summer was going to be the dullest of her life. Instead of watching scary movies and exploring haunted houses with her friends in Clinton, she has to spend the summer in Milwaukee because her genius foster brother, Cowper, is taking piano classes at the conservatory. Now she's stuck with her family in an old apartment building that looks like it's falling apart. The people living there are kind of weird, too. In fact, the lady in apartment 405 seems to have unusual powers—because whenever Erin goes to visit her, strange things seem to happen. Then one creepy night, when there's nowhere else to go, Erin makes a surprise visit to apartment 405. . .and that visit may be her last!