To those who have been saying "The Ponds really didn't need to be in this episode," I almost wonder if that's the point. They are no longer the Doctor's companions who live in the TARDIS and travel around with him. They are just people that he sometimes picks up when he wants to have an adventure. They absolutely don't need to be there. They're there to tag along for a while and then go back to their normal lives, and I think we're going to see more of that in the next couple episodes.