Ben and Jilly have stumbled across one of science’s biggest secrets and now they must protect it from a spy – Mr Z.

This hi-lo series for struggling and reluctant readers has been written for children aged between 8 and 14 years, whose current reading age is between 7.5 and 8.5 years. These age-appropriate short reads have 32 pages and are written by brilliant authors. They incorporate a large font size and text separated into bite-sized chunks, along with carefully considered letter and paragraph spacing that can reduce visual stress. The series has plenty of practice at one level, allowing consolidation of learning before moving on to more challenging reads. The vocabulary list of tricky words can aid comprehension before reading the book.