I'm confused about what this is. Is it a retelling of the story from the Kalevala? Or is it just inspired by the Kalevala? The description keeps saying "Tolkien's Kullervo", but Kullervo isn't Tolkien's invention. Ah well, I'll almost certainly buy it anyway.
This one is probably my favorite non-Middle-Earth Tolkien work. It's fascinating for two reasons: it's Tolkien's retelling of probably the most well-known legend to come from Scandinavia, and he actually uses an old Norse poetic meter, albeit with the English language. Tolkien as linguist, poet, and story-teller all rolled into one. Not to mention it cements the notion that Middle Earth was heavily influenced by Tolkien's interest in Norse myth and legend. That and the story itself is just plain bad-ass in a way that only the Vikings can be.