Complex sentence: Silas is never able to clear up the details of the robbery that caused his exile from Lantern Yard, as his old neighbourhood has been "swept away" and replaced by a large factory and no one seems to know what happened to Lantern Yard's inhabitants.
Split into simpler sentences: Silas is never able to clear up the details of the robbery that caused his exile from Lantern Yard, as his old neighborhood has been "swept away" and replaced by a large factory. No one seems to know what happened to Lantern Yard's inhabitants.