Ah. [... And his own tone becomes playful as he rests his palm on Billy's forehead.] So you're the high level Pikachu.

[See, Teddy doesn't mind the Pokemon references, as this just makes the lesson ten times better than anything any other teacher could do. But since it's true that Billy knows jack about Pokemon, he'll go back to stroking his hair and looking at the book. He kind of just wants to skip and see how to help dress a wound like that already, but might as well learn up on it as well.]

If it's all internal, then it'd be hard to tell how bad it is, right? Since it follows the current of the body, so it's in a different place than the entry or exit wound. Like a maze where just the start and end points are visible.