A massive explosion erupts as they break through the Earth's crust. The Doctor, Sutton and Stahlman go into the drillhead to try to cap it. Stahlman attacks the other two and seals off the drillhead when they leave. He begins pushing the unconcious technicians into the green slime oozing from the drill.
The Doctor realizes that the planet is doomed - there is no way to contain the forces unleashed. Sutton wants to leave but the Brigade Leader seals off the complex and insists they keep working. The Brigade Leader's interest is piqued when the Doctor suggests they help him use his TARDIS to return and save his own world. A short demonstration convinces the him it can be done. However, it's clear his main interest is in saving himself.
Stahlman calls out to Petra to raise the heat shield. When she does, he and the other technicians emerge completely transformed into hideous monsters. They attack and transform Benton while the others escape into the Brigadier's office. The primords bide their time, letting the growing heat build their strength.
In the real England, Sir Keith has gotten permission to shut down the Inferno project. Stahlman, however, has ordered his driver to keep him from returning. Sir Keith persuades the driver to support him, but the man gets into a car accident while turning around.
In parallel England, the survivors agree to help the Doctor return if they can get past the primords. Before the Doctor can plan an escape, though, a green claw smashes through the office window...