It is set in the same world, you know Bitten is about Elena (the female werewolf)? Well this book is about Clay, who is Elena's OH, and Jeremy, who is the pack Alpha. You could read it before or after as most of it is set way before Bitten, but the last short story in the book is set after No Humans Involved which is the 7th book in the series, so it's pretty much your choice I will say though, that the last story does give away something that is built up through the other books, just as a warning ^^