Strange Adventure

Sam and Luke vanish: there one second, gone the next. That's the last thing Kitty Strange expected to happen while in her lounge after school with her best friend Lizzie, Luke's twin sister, and Toby, Kitty's twin brother. Where have her younger sister and Luke disappeared to?

Minutes later, Kitty, Toby, and Lizzie materialize in a parallel world, with just one clue as to where Sam and Luke are. What do they do next?

Launch a rescue mission, of course, that leads them to an academy for gifted...