The Red Pyramid: the first book in Rick Riordan's The Kane Chronicles.
Carter and Sadie Kane's dad is a brilliant Egyptologist with a secret plan that goes horribly wrong. An explosion shatters the ancient Rosetta stone and unleashes Set, the evil god of chaos . . .Set imprisons Dr Kane in a golden coffin and Carter and Sadie must run for their lives. To save their dad, they embark on a terrifying quest from Cairo to Paris to the American South-west and discover the truth about their family's connection to the House of Life: an Egyptian temple of magic that has existed for thousands of years.The pharaohs of ancient Egypt are far from dead and buried. And neither, unfortunately, are their gods . . .
