There are 49 hours and 15 minutes to penetration and Sir Keith decides to go to London to get authority to close down the project as Stahlman, already showing signs of 'infection', will not listen to reason. The Doctor wakes up, apparently in the same place. Outside, he is chased and shot at by troops before being found and arrested by someone who appears to be Liz Shaw. The Doctor realises he has slipped sideways into a parallel world. The Doctor learns that Sir Keith has been killed in a motor accident on the way to London and that there seems to be nothing to stop Stahlmann.
Alarms ring out as number two output pipe hits problems.
In the confusion, the Doctor manages to repair the computer and it immediately advises that they should disperse the pressure and heat by creating a reverse vortex at the bottom of the drill shaft by reversing the systems. This works but Stahlmann intends to restart the drilling as soon as he can. The Doctor is taken to the security cells, from where he escapes when the man in the next cell turns out to be infected by the slime. With three minutes to penetration, the Doctor again appeals to everyone to stop the drilling, but is ignored. At penetration, earthquakes rock the centre and the Doctor and Sutton try to get the coolant flowing once more.