For the past week, the expedition has focused on Nyiragongo. Now Chris Jackson and his fellow geologists are heading to the nearby volcano Nyamulagira, one of the most active yet least explored volcanoes on the planet. Few have visited this volcano, for a good reason - the forests that blanket its slopes hide a number of armed groups. The team travel on a UN helicopter flight at treetop level to avoid being hit by groundfire, before landing as close to the active crater as they can. They then have only a few hours to gain as much data as possible to help predict future eruptions.