King Arthur awakes in a post-apocalyptic Britain? I'm in!

Sadly, it's for young adults, so we can't focus much on Arthur. Rather, the plot follows a boy whose family is exiled from their city when his sister is born with six fingers. Arthur shows up in the beginning and then disappears for half of the story. When he comes back there's mostly mythbusting going on. "I was never a king, is that what they said of me," and all that.

I enjoyed the setting change to the Isles of the Blest. These are Isles of Scilly U.K., as indicated by trips to and from Tresco & Hell Bay. The climactic reveal involves a piece of modern equipment these characters know as "Merlyn's Tower" which I suspect is the BBC radio tower on St. Mary's.

The denoument was unsatisfying, though I understand it is a setup for more books in a series.