JD Robb’s Golden in Death is free right now in the US and Canada, at several e-book retailers. And the audiobook is also supposedly free at Kobo US, although I haven’t personally tried downloading/listening to it yet. I had a review copy of Golden in Death when it came out back in 2021, and liked it a lot.
Buy at: Kindle US | Kindle Canada | Kobo US | Kobo US/audiobook | Kobo Canada | Google Play books
And my thanks go to @library addict on the MobileRead forums, whose post alerted me to the freebie.