A companion trilogy set in the same multiverse, functioning as both prequel and sequel to His Dark Materials. La Belle Sauvage, the first volume, is set a decade before Northern Lights and follows a young boy protecting the infant Lyra during a catastrophic flood, establishing the theological and political forces that shape her world before she is old enough to understand them. The Secret Commonwealth, the second volume, follows an adult Lyra in her twenties and is the darkest and most complex work in the wider universe. The third volume remains unpublished.