With so many exoplanets out there in the galaxy, it seems reasonable to hope that life may be prevalent. On our planet, it took a series of unusual coincidences to give rise to our intelligent civilization, and it’s quite unlikely such serendipity has taken place elsewhere. Science writer and astrophysicist John R. Gribbin examines how everything had to go just right. Perhaps most unlikely of all, he argues, was the development of our technological species—a feat that is probably unique in the Milky Way.