Clocks and mirrors,
This review is from: The House of Mirrors (Ulysses Moore) (Paperback)
The third book in the Ulysses Moore series doesn't allow for any breathing space after the end of Long-lost Map. Jason, Julia and Rick continue to hunt for clues and artifacts that will hopefully reveal the secrets of the Doors to Time, but as they will discover, there are more secrets in Kilmore Cove than they could ever have imagined.
Given some extra time when their parents are delayed by the moving company, Jason and Julia put aside their sibling squabbles for the moment and together with their friend Rick, they set off on the trail of Oblivia Newton, the femme fatale who seems to at the root of all their troubles.
Their quest leads them to the Mirror House, an amazing feat of engineering involving solar panels, mirrors (naturally), lots of doodads and whatnots, and somewhere deep inside, a secret that Oblivia is prepared to move anyone or anything in her path to uncover.
The inventor of the house and aforementioned doodads and whatnots had disappeared some time before our story begins, and the young adventurers are faced with solving the mechanical puzzles that he left behind.
Packed with lots of action, intrigue and challenges, this is suitable for readers from 8 to about 12, but I would recommend reading book one and two before attempting this one.