The rapid demise of a giant, carbon-spewing algal bloom points to the influence of viral wranglers, scientists report August 21 in Current Biology. Over 25 days in the summer of 2012, the team tracked a giant mass of Emiliana huxleyi phytoplankton off the coast of Greenland with a satellite. Emitting 24,000 tons of carbon at its peak, the bloom was well nourished during its lifespan. Then, the mass suddenly died within eight days. Measurements taken immediately after the die-off revealed an abundance of algae-attacking viruses, suggesting that viruses may determine the fate of phytoplankton blooms and their carbon emissions.