Scratch is the fourth volume of the Guardian Interviews, which is basically a World War Z series of vignettes starring a group of monster hunters who successfully saved El Paso from an outbreak of zombies. While they managed to contain the zombie outbreak fairly early, they've since gone on to have a number of Supernatural-esque adventures. As the title suggests, this book deals with a new monster in the form of the universe's version of werewolves.
I have to say I'm impressed with Michael Clary's lycanthropes because, aside from the Autobiography of a Werewolf Hunter series, I can't remember another novel where the werewolf has been portrayed as such a formidable threat. Werewolves in this universe infect a person, they become an unstoppable killing machine, and not even the Guardians are equipped to deal with something like it.
My criticisms of the previous book are still present as the interviewee really goes out of her way to lavish affection and praise on the Guardians at the start. I'm not a big fan of this since the characters are entirely capable of standing on their own accomplishments. It also makes the interviews seem like fluff pieces when you'd think they'd be more interesting if the interviewer criticized our cowboy-esque heroes every now and then.
Despite this, the primary appeal of the Guardian Interviews is and always shall be its action and this is probably the best book for that. The werewolf hunts are impressive ones with it never in doubt the heroes are outmatched. There's a contrived coincidence when they go after it without silver bullets the first time but that can be blamed on the rising body count and the fact they're overconfident.
I also give credit to the depiction of the monster itself as he's depicted as a sympathetic figure who has been horribly cursed. So cursed that he isn't even able to commit suicide to prevent more innocent lives from being lost. The fact we also get to see what happens when a werewolf is completely unfettered from human mores is also one of the more terrifying moments in th book.
Fans of military science fiction and urban fantasy-esque stories will probably enjoy Scratch a great deal. It's a nice R-rated story which doesn't hold back on the terrible things our heroes encounter. They're a nice enough bunch, albeit far too confident, which also makes the story extra enjoyable. I wasn't fond of the author referring to a group of people as "Gypsies" but I don't think the author or character was aware it was a slut.
In conclusion, Scratch is one of my favorite of the Guardian Interviews and I hope Michael Clary continues the series. It's full of action, likable characters, and terrifying monsters. I would like to see the heroes suffer a more permanent loss than the kind they've been experiencing throughout the four books but that's just the grimdark horror fan in me.