A rare treat: cutting-edge science combined with a perceptive portrait of the people who perform it. Dressier (Astronomy/Carnegie Institution) was one of a team that set out to perform a survey of elliptical galaxies and ended by revising a fundamental axiom of modern cosmology. The ""Seven Samurai,"" as they became known on the release of their results, combined expertise in observation and theory, bringing an unusual level of astronomical talent to their task. Dressier gives brief biographies of himself and the other team members and devotes considerable space to detailing their personal interactions over the course of the project, providing an unusually candid look at not only what scientists really do, but how they feel about it and about each other. As the data from their survey accumulated, the team's initial goal of discovering clues to the absolute magnitude of distant galaxies began to fade as they realized that a large number of galaxies were traveling at unexpectedly high velocities -- 1,000 km per hour or more -- that could only be explained by the attraction of a huge mass. Equally important, this discovery forced a reconsideration of the assumption that the velocities of distant galaxies are almost entirely due to the expansion of the universe and directly related to their distances from Earth. The implications of the discovery, and its theoretical underpinnings, take up much of the last part of the book, a generally clear overview of current thinking on the origins of the universe. A readable and engaging glimpse behind the facade of contemporary science; Dressier does for astronomy what James D. Watson's The Double Helix did for molecular biology.