McDevitt won an award for this book; it's the third in a long series but I read it stand-alone. It's terrific. The discovery of a souvenir cup (!) leads to the most profound discovery in human history, and the layers upon layers, events upon events, actions, reactions and inaction in-between is masterfully written. Again with McDevitt's starting with the acorn of a premise: What if they found an artifact from a ship thought missing thousands of years ago? I need to learn to write that way.