All aboard for a new off-the-rails case in the third installment of this middle grade mystery series for fans of A Series of Unfortunate Events and Enola Holmes.

Stranded on a mountain in Peru, John Boarhog has only one mission on his mind-reuniting with his mentor and guardian, Inspector Toadius McGee. John's convinced that if he makes his way to the plume of smoke in the distance, the great detective will be waiting. But he can't get there alone. Along with his new friends, he brokers a deal with the Mauve Moth and they craft a plan.

Instead of the Inspector, they find a train- The Peruvian Express.

After Toadius and John reconnect along the route, the train's cargo of gold is stolen . . . and their group are the prime suspects!

Now it's up to John and Toadius to root out the real criminals on a speeding train where no one (apart from them) has come or gone, all while barrelling toward what could be their own doom.

The third book in The Curious League of Detectives and Thieves, The Peruvian Express is a hilarious, fast-paced mystery packed with action, wit, and another unforgettable adventure.