Inclusion conjures images of children with special educational needs and disabilities (SEND) learning in classes alongside peers in a mainstream school. For pupils in the UK with high-level SEND, who have an Education, Health and Care Plan (formerly a Statement), this implies an everyday educational experience similar to that of their typically developing classmates. Yet in vital respects, they are worlds apart.   Based on the UK’s largest observation study of pupils with high-level SEND, this book exposes how attendance at a mainstream school is no guarantee of receiving a mainstream education. Observations of nearly 1,500 lessons in English schools show that these students’ everyday experience of school is characterized by separation and segregation. Furthermore, interviews with nearly five hundred pupils, parents, and school staff reveal the effect of this marginalization on the quality of their education. The book argues that inclusion is an illusion. The way schools are organized and how classrooms are composed creates a form of structural exclusion that preserves mainstream education for typically developing pupils and justifies offering a diluted pedagogy for pupils with high-level SEND. Ultimately, the book suggests why a more authentic form of inclusion is needed, and how it might be achieved.