Lottie and Lulu never expected their afternoon at Nanny and Poppy's house to turn into a whirlwind adventure-but when they discover an old stamp album hidden in the attic, their lives change forever. With a single touch, the sisters are magically transported to London, where they stumble into a daring heist involving one of the rarest stamps in history-the legendary Penny Black. But there's a problem. They don't have a way back home. With a mischievous boy named Max guiding them through the bustling streets of London, Lottie and Lulu must navigate secret societies, royal mysteries, and a high-stakes chase through Buckingham Palace itself. As they unravel the clues behind the stolen stamp, they soon realise the world of stamp travel is far bigger-and more dangerous-than they ever imagined. Will they crack the case, recover the missing Penny Black, and find a return stamp before time runs out? Or will they be stranded in London forever? The Stamp Travellers: London Heist is a thrilling middle-grade adventure bursting with mystery, humour, and a big dose of magic. Perfect for readers who love fast-paced action, daring escapes, clever problem-solving, and unravelling mysteries alongside unforgettable characters.