Casting the Gods Adrift - Geraldine McCaughrean

A thriller set in ancient Egypt between 1351 and 1354 BC. Tutmose and Ibrim's father, the animal dealer, is commanded by the new pharaoh Akhenaten, to bring him animals - lots of animals - for his new capital city. The boys' father is delighted. But he has no idea what the pharaoh's strange new religion will mean for all of them.