The Frugal Wizard's Handbook for Surviving Medieval England

 The Frugal Wizard's Handbook for Surviving Medieval England by Brandon Sanderson, 372 pages.

A man wakes up in what looks an awful lot like Medieval England with no memory of himself whatsoever. His name would be good to know, but it seems a little less important than the pressing questions of "what am I doing here?" or "how did I even get here?". These questions become more relevant as it becomes obvious that there are some other people from the future running around, and the memories he's getting back seem to be hinting at a dangerous life he left. 

This was the second of Sanderson's four secret novels, and I really loved it. I really like the concept of time tourism, and I liked even more that (minor spoilers) Sanderson chose to use alternate dimensions instead of literal time travel. The worldbuilding is interesting, and the book is pretty darn funny throughout. However, despite the humor, he manages to set up genuine emotional stakes with a really solid payoff. Some fans are apparently less thrilled by this one, I suspect because it's tone is pretty different from his normal fare, but it reminds me quite a lot of his Alcatraz vs the Evil Librarians series (an extremely funny series of middle grade novels) and I would definitely recommend it, especially for fans of a fun sci-fi romp.