I was really glad that Mathias was back in the series after he'd helped the Order so long ago. I had forgotten he'd not gotten his own story so this was a pleasant surprise. 
 While I like Mathias and Nova their love story seemed very rushed and not as well thought out as past stories full or otherwise. 
 I did like the overall story of the deaths and Mathias figuring out what was happening though how it connected to Nova seemed to fall flat and left a few unanswered questions. 
 Overall a decent novella and one that I would read just because I love the series.