This story has a wonderful start (not counting the prologue); when New York attorney Allister Park wakes up things seem a little different. First he is wearing a pair of pyjamas he doesn't own and then to confirm it, he now has a moustache - one he didn't have the night before. Also he is now Mr. Arthur Vogel.

This continues daily until he becomes a Christian Bishop in an America originally colonised, although not completely, by the Vikings in the 10th Century. He then has to survive in this strange land, learn the language and figure out why he is there.

Now I have a great liking of alternate earth stories and de Camp's take on this is very good. He uses a pivot in history to divert from the world we know I found to be very original (I hadn't even heard of it) and develops his world in a highly believable manner.

The characters are believable, the situation consistent, and (due to its being a novella) the action is fast paced. The only criticism I might even start to level is that the lead character is a little too succesful in his dealings in the world in which he finds himself, but this is a minor point. This is good SF, it maybe a familiar concept now, that of alternate earths, but de Camp wrote this in 1940 and it still holds up exceptionally well. This is well worth reading.