It has no alien elements at all, the Doctor and his companions are effectively sideline players in this story except for the Doctor impersonating Salamander in the last episode. You could argue had the Doctor not been there then Salamander may not have died, but from Earth's perspective he simply died in the research centre explosion (no worse than Hartnell suggesting the fire of Rome to Nero or the large wooden horse in Troy).
Anyone agree?
Anyone agree?