Much like everything I have read so far by David Mitchell, I loved this.

The last part of the book, "Sheep’s Head, 2043", is one of the darkest, bleakest, and yet most plausible descriptions of a post-oil post-civilization near-future I have ever read, and its ending is surprisingly emotional - I suppose because by then we have spent over 600 pages and 60 years with Holly Sykes, from teenage runaway in Kent in 1982 to grandmother in a dystopian Ireland in 2043, via many other parts of the world (or should I say "worlds" - this is a fantasy novel in many parts).