This is a novella that takes place before the evens of the first book of the series. It can be summarized in a few short sentences. One of the most interesting and flesh-out characters of the first book - Marco - joined NYC Sky Ghosts.
By joining he got a stable life, income, and boredom luckily spiced up a little by his rivalry with another main character of the first book - Pain. These two had serious competition trying to out-bully each other. Free entertainment for the rest of Sky Ghosts followed.
The novel is fairly short and unfortunately it does not show where Marco came from even though the majority of the book is spent on his POV. It is still great to watch the rivalry unfolds and the crazy pranks these two play on each other. As such the novella is a short fun read - there is nothing more to say. My rating is 4 stars
for the mentioned fun factor; these are weak 4 stars, but 4 stars nonetheless. Despite this novella being a prequel I feel it is better to read it after the first book which gives much better overall picture of the whole Sky Ghosts organization and its challenges.