Complex sentence: Wade's subsequent incarceration forces him into a world unlike any he has known before, first the crowded confines of the county jail and then' The SHU', the high security unit of San Quentin State Prison.
Split into simpler sentences: Wade's subsequent incarceration forces him into a world unlike any he had known before. First the crowded confines of the county jail, and then' The SHU', the high security unit of San Quentin State Prison.