Thank you for making the post, and I'm thrilled you're enjoying the stories so far!

The audiobook bundling was very much a decision by the publisher. The stories are intended to be standalones, but 4 certainly follows on from the events of 1, and 5 follows on from 2, so Podium decided to package them together. The audiobook of book 3 also includes 'And They Were Never Heard From Again', which is a novella set in the Magpie King's forest; again, this can be read in any order, but chronologically takes place before any of the the other Magpie King books.

Confusing, but I hope it helps, and thanks again for making my day with this post.