The frozen frontier, and cosmology's boldest bet yet: Antarctica. It was my longest journey for the book, from London to LA to New Zealand, then onwards to Antarctica. And it was the most extreme. Antarctica is alive with recent history. Scott and Shackleton are everywhere, reminders of the triumphs and tragedies of the Heroic Era. This unforgiving continent is now the site of some of cosmology's most daring experiments. At McMurdo, I saw the launch of a balloon experiment named BESS, designed to look for primordial antimatter, to solve the mystery of what happened to all the antimatter that was supposed to have been produced after the big bang.