So they're changing the code and sending the key to it across with this somebody or other.

That's about the size of it.

He's got a lot of information, too, in his head, where we can't get at it." "But his credentials will have to be something that can be seen, won't they ?" Tom ventured to ask.
"Prob'ly.

You see, he means to desert or get captured.

It's a long way round, but about the best one--for him.