An entertaining prequel to 'Startide Rising' and the 'Uplift War'. If you've read those books, two of the greatest sci-fi novels in the last 3 decades, this will be an enjoyable piece of background. And if you haven't read those two novels, this is the perfect place to start the exploration of David Brin's amazing universe. As the title indicates, this novel focuses on mankind's first ship to sail inside the sun itself but that is just the beginning.