Persuaded by Jack despite Ricky's protests, the team decides to destroy the swarm or else risk its reproducing exponentially and becoming a grey goo plague that could endanger humanity. They believe the swarm must have nested in the desert to reproduce. They attempt to find this nest by tagging the swarm with radioactive isotopes and following them back to their nest at night. Under the cover of a strong wind that forces the swarms to remain dormant, the team goes outside to a storage shack to find the isotopes and build a spray device. However, the wind dies down, and four swarms attack the shack and eventually kill David and Rosie. The rest of the team are forced to take shelter in the cars parked outside.