Rocket Robinson and the Secret of the Saint — Sean O'Neill

Paris, 1933

Rocket, Nuri, and Screech return in the second volume of the Rocket Robinson series. This time, they find themselves in the French capital, where a rare and mysterious painting from the middle ages has been stolen from the Louvre Museum--and Nuri's uncle is the prime suspect!

The young adventurers are soon hot on the trail of the stolen artwork--a trail which leads to a pair hapless French thieves, a secret cabal of merciless German spies, a shadowy secret temple, and an ancient medieval castle! But this is no ordinary painting... the secret contained within may lead all the way to the most mysterious and sought-after treasure in history.