After talking to Cassandra, Kristoff returned to his lab and looked at the coins for just a few minutes in thoughtful silence.

And then, of course, Manners required one thing. He wrote four words neatly on a piece of paper, which he slipped into an envelope and put in his coat, before locking the bag of coins away in one of the lab's various secure drawers.

Then, after running a little more data about circumventing the nanites, Kristoff gathered some of his notes to bring with him as he left the lab.

Soon he knocked on the door of his brother's bedroom.