And that is why Donna should never be allowed to form any kind of welcoming committee. "Yup. Apparently the lovely people here calling themselves the System or some nonsense swipe innocent people from their homeworlds and bring them here to fight a flippin' giant snake that wants to destroy all worlds."
She made it all sound so simple. "Mandalus is like the crossroads of all worlds... or sommat... and if we lose to the Serpent it'll destroy every world in every universe. So we get stuck here and fight or die. Defeat the snake and we can go home."