It's difficult to see how any Doctor Who writer could have possible envisioned the Slitheen, or the Slitheen episodes, without being taking seriously worrying levels of narcotics. They're literally big balls of fart, a quality so inherent to their evolution that it's how The Doctor is able to work out their species and home planet. Speaking of which, Raxacoricofallapatorius is, doubtlessly, something that one of the writers mumbled into their hand when they realised they had not come up with a final idea for a name The plotting of the episode does not redeem it, and sounds like a potheads idea for a fantastic blockbuster movie. Imagine the pitch: So theres this space pig, and it crashes into Big Ben, and then it dies, but its not really the villain, its actually these fart monsters that are using the leaders of the world as zip suits and then want to start a war or something or hey, does anyone want to get Subway? And frankly, if this episode wasnt the result of soft drugs, then Russell T Davies conscience has to live with the fact that he wrote this completely straight faced for the rest of his life. That probably warrants some MJ just to help him forget.