Blackout! Castle Under Siege! Wackiest Machines Ever! These books take an exciting new approach to physical science curriculum topics, including materials and their properties, simple machines, energy, forces and motion, electricity, sound and light, and gravity. Raintree Fusion is high-interest nonfiction aligned with curriculum, at a reading level accessible to struggling readers.Solway, Andrew is the author of 'Castle Under Siege! Simple Machines' with ISBN 9781410919496 and ISBN 1410919498.