GREG sighs.) I may be able to stop them before they penetrate the Earth's crust. PATTERSON: Different route, sir - trying to avoid the traffic. SECTION LEADER ELIZABETH SHAW: You said we'd passed the point of no return. The DOCTOR uses the diversion. The DOCTOR watches them.
Plan: A: The earth's crust; Q: What has been penetrated? A: the Doctor; Q: Who begins to realise the planet has passed the point of no return? A: the disaster; Q: What is the Doctor and Greg trying to contain? Summary: The earth's crust has been penetrated and, while the Doctor and Greg try to contain the disaster, the Doctor begins to realise the planet has passed the point of no return.