For a limited time only, presumably.  Presumably Amazon will follow suit before long and lower its price to zero, but you should probably go ahead and pay real money for it anyway.

Here’s a recent 5-star customer review from Amazon:

In this new entry in the Young Adult fiction category, Richard Bowker explores questions of our relationship to the world we live in by telling the tale of a young adolescent who discovers a portal to an alternate version of that world. By creating that world as one with underdeveloped technology, he is able to paint a vivid picture of what life might have been like in the mid 18th century in colonial New England (even though the portal is not a time-travel device). His characters are well-drawn, and his descriptions of battle scenes between the New Englanders and the Portuguese soldiers are gripping, especially with regard to the angst his protagonist, Larry Barnes, feels about having killed an enemy. In the end, Larry has to make a choice — one that is surprisingly difficult and thought-provoking and which wouldn’t have been anticipated earlier in the story.