Promise of the Betrayer's Dagger

So... I wound up with this book during some promotional event of some kind where I got it free. Nothing on the page said that it didn't work as a standalone - nor did the Goodreads synopsis and it isn't tagged as being part two of a linked series. So I snatched it up because it sounded good and I do know that some ‘series' can be read in any order or are functionally standalones in a single world (which is what I thought this was).

I have since discovered that this does not work as a standalone. As such, I'm not even going to attempt this book and...well, I also have no interest in spending the five bucks (I think?) for the first book just to read this random free book.