I know it seems like there are a lot of updates at the moment, but I promise the reasoning is that there's a lot of good stuff ahead and both Arizona and I want to bring the best to everything we're doing.
Long story short: if you're looking at Grave Mistake on retailers then you might now find it at the end of the Amethyst's Wand Shop Mysteries series.
When we put Grave Mistake up for pre-order, we thought we were going to be finished writing Amy & Ambrose's series before we got to it (we originally planned up to 6 books for them, but have sinced realised that there's no way we could be done at 6 (or 8, which is the last one currently on pre-order).
We always planned for Grave Mistake to have a standalone crime in it (like the books in Amy's series), and so we've decided that (for now), we're going to write it as a standalone for Stacey and Gabriel (who we are desperate to write for because they've been very loud about what their story is!) and have it as part of the main series. We might revisit them as main characters in the future too.
The longer story: both Arizona and I have been taken off guard this year by how well some of our series have been doing (both together and separately) and have come across some particularly chatty characters who need more than 3 or 4 books to tell their story properly. We sat down to work out our scheduled yesterday to allow for the extra Purple Oasis books we want to write, and realised that juggling three co-written series on top of four long-running series for me (The Apprentice Of Anubis, Obscure Academy, The Shifter Season, and Forgotten Gods), and two for Arizona for certain (The Griffin Sanctuary & Queens Of Olympus) and another two for her potentially (The Forked Tail & Crescent Lake Shifters), plus her Aliens and Animals series with Skye MacKinnon, just wasn't going to be possible while not making anyone wait too long between books in a series.
Rather than cut Amy's series short, which we didn't want to do because there's just so much to tell for her), or cut the extra books to Purple Oasis (which we want to write because we love the world building), we decided that Stacey and Gabriel (Grave Mistake) could work perfectly as a standalone addition to the Amethyst's Wand Shop Mysteries series. (I promise it isn't going to end up cancelled, we have given a lot of plotting time to Stacey and Gabriel already. and we're super excited to deal with their dynamic, and we also think it'll be interesting to see Amy & Ambrose from the outside!)
Anyway...basically, there's lots of good stuff coming, but we want to give ourselves the best chance to manage it and produce the best books and series we can, which is why there have been a few changes in the past couple of weeks!
(Speaking of, you might also notice that Twin Souls, Dragon Soul, and Renegade Dragons are now listed as one series on retailers, this is just us streamlining and putting all of our dragon shifter romances set in the same world in one place! The only change has been putting the Dragon Soul books in the actual order they happen in, which I don't think has ever been the case before!)