Tesla's attic

"With a plot combining science and the supernatural, four kids are caught up in a dangerous plan concocted by the eccentric inventor, Nikola Tesla"--

After their home burns down, Nick, his younger brother, and their father move into a ramshackle Victorian house they've inherited. In the attic room, he finds a collection of old junk. After getting rid of them in a garage sale, Nick and his friends discover that all of the objects have extraordinary properties. What's more, Nick figures out that the attic is a strange magnetic vortex, which attracts all sorts of trouble.