The Kindle version of The Red Cliffs of Zerhoun by Matthew Bracken is available for free today on Amazon.

British readers in particular will be interested in this novel, given the setting and the characters. Here’s the British Amazon link.
The American link is here.
It appears to me to be free only with KindleUnlimited. Did I get this wrong??
It’s confusing. I already bought the Kindle version when it was for sale. This thing doesn’t seem to give you an option.
Here’s what I’d do (based on experience):
Try clicking on the “Buy Now” or “Read Now’
You’ll get a notice that it’s been sent to your Kindle. Then you can check your Orders page and see if there was a charge made to your account. If there was, then cancel. In the past, when I’ve accidentally purchased a Kindle item, I go to my digital orders and bring up the purchase, if it doesn’t say 0.00, then hit CANCEL.
They give you at least half an hour to do that.
Thanks Dympha: that worked!
ORDER PLACED TOTAL
December 8, 2017 $0.00
It appears to be free only with a 30-day free trial. Is that right?
See both Matt and my reply to Liatris. Purchases are retractable.
No, it’s free for anybody, on the USA or UK Amazon.
Friday and Saturday, until midnight California (Amazon) time.
It’s only free of charge in Britain if you have Kindle Unlimited which I don’t. I do not propose jumping through hoops like a previous “poster” does. If I decide to read it and that is a big “if”, I’ll buy it for £1 in a charity shop. In my experience this publicized offer would appear to be, like many other offers in rip-off Britain, a hoax.