Sinkov provides Waterhouse with a desk in the whorehouse and begins to feed him the messages that Central Bureau hasn’t been able to decrypt. There are still dozens of minor Nipponese codes that remain to be broken. Maybe, by breaking one or two, and teaching the ETC machines to read them, Waterhouse can shorten the war by a single day, or save a single life. This is a noble calling that he undertakes willingly, but in essence it is no different from being an Army butcher who saves lives by keeping his knives clean, or a lifeboat inspector in the Navy.