Iceland has become one of the best places in the world to study Covid-19. That’s because the country is an island nation with only one real port of entry and a small population. It also introduced widespread testing as soon as the virus arrived in March. Bloomberg reporter Kristen V. Brown traveled to Reykjavik, the capital, just as the global scale of the pandemic was starting to become clear. She reports that the rest of the world is learning from Iceland about how the virus moves through a population.