He knows pain intricately, from being on the receiving end of it one too many times. He switches it up before it can be either too much to bear, or too monotonous. Mick's other thigh gets the same treatment after twenty, and even Leonard switches hands after a while.

It's becoming a little zen for him now, easier to zone out, when he listens to Mick's voice and takes careful note of when it threatens to become too much for him.

But he knows that tone of voice; it's right after Mick's set a gigantic blaze, and is settling in to watch it all burn. Bit by bit, Len starts to understand it.