When the TARDIS lands on Orkney in the near future, the Doctor and Amy arrive to find a large demonstration in progress over the construction of new electricity pylons. The Doctor tries to break things up peacefully - but suddenly the road splits open without warning and swallows police, security guards, and protestors alike. Separated from the Doctor, Amy takes charge of transporting the wounded to hospital - but the rescue mission becomes a terrifying ride as the pylons come to life and begin to walk and the road rears up, erupting with boiling tarmac...