X-link to the Kids/YA-megathread, since Attanasio is a multiple Nebula-finalist who's been pretty generous with the backlist freebies and this seems to be a tie-in to his HarperPrism-published Arthurian fantasy quartet we previously received free:
Free from the author via KDP Select @ Amazon:
Lancelot du Lac by A. A. Attanasio with illustrations by Jesse Lindsay, 1st in their Provenances of the Perilous Order series of YA Arthurian fantasy