So it looks like Macmillan moved his page to here:
I decided to check out the listed retailers for this, his final published book.
Target has no listing for it. Powells has no listing for it. Bookshop.org has no stock on it and has it listed as on Backorder. This means they have no stock, either from selling what they had (unlikely) or they returned their stock for credit (likely) and now have none, and the publisher has none either. They are not making more and have none.
With a book like this, it can sit on backorder forever sometimes unless demand exists to push a print run. Which won't happen.
Books a Million has no in store stock and can only order it to be shipped. Likely existing warehouse stock they're sitting on. Could even been a remainder they bought, as BAM will sometimes do that.
Barnes and Noble had it in no stores in the major metro areas I checked, except for a single copy in the Bayshore Mall location in Glendale WI which, I bet if I went and checked, is an author signed copy since Fats lives in the area and likely drove around and signed copies at local stores. BN will usually not send these back, or has them sitting on a Local Authors endcap or table display.
Amazon has a single copy NEW left but it's from HMK Trading Corp, likely a remainder purchased from a first run retailer or the publisher themselves.
Into the Black is, as far as I can see, out of print and unlikely to see print again.
Oh and this is always a good sign:
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