Jackdaw by K.J. Charles is another spin off novella in the world of Magpies.
It is a self contained story and theoretically can be read as a stand alone, but I'd not recommend that. It would doing spoil quite some big moments in Flight of Magpies, and I think it's also more enjoyable if you read the series first. 

The author did a wonderful job of turning the tables, and putting is on the shoes of the villain. So now you both root for the cast if the main series, while also rooting for Jonah, who you definitely didn't like after what he did. 

That she manages to make him so human and relatable, you end up falling for his charm right along with Ben is proof of how amazing her character development is. 

Once again a rather graphic and steamy m/m romance. I personally could do with a lot less graphic detail, but they are at least well written, and the story, characters and world just hooked me again right from the start.