Videoing volcanoes
Geoff Mackley and Drew Bristow are behind video footage taken from inside the crater of the Marum Volcano on the Pacific Island of Vanuatu.
In the video Drew, dressed in a heat suit, waves casually at the camera as a sea of molten lava appears to bubble and seethe only metres behind him.
The film has become a huge internet hit, even though the footage is so incredible many people have accused them of faking it.
It is billed somewhat immodestly as the most incredible volcano footage ever.
And it comes 13 years, and many failed attempts, after Geoff first tried to get close to one of only four permanently active lava lakes in the world.
Matthew Bannister spoke to Geoff and Drew from Auckland in New Zealand about the extreme conditions of working on active volcanoes.