Miss Rose, there is only one real London. Being pulled into an alternate realm is another matter entirely. I'm not quite sure what you mean by your Merlin, either. There has, surely, been more than one by that name.
Ah. I'm awfully sorry about your father. I have a brother and a sister. Cygnus is my brother, and we used to spend a lot of time together but I don't see much of him any longer. He's seventeen, and has left school now and is married. My sister Misapinoa is ten, and she's a good girl, but we aren't interested in the same things, really. Still, I shall look after her next year when she starts school.
Doctors drain people's blood and cut off their limbs, I wouldn't visit one if I were paid to! You're rather brave if you do.
Yes, we have spells for those things! You have to be careful of the temperature, though, because a warming spell will make you feel comfortably warm, but it doesn't prevent the cold from affecting you and giving you frostbite if it really is freezing.