Brack (or Braack, as I've seen his name spelled elsewhere), is more than just an assistant. He is Exeter's master-at-arms, in charge of security for the Club House and the ship.
But I also make him out to be a Soviet-style Zampolit and KGB Rezident all rolled into one. "Your papers, please." He is every policeman, Gestapo man, SS guard, East German Stasi man, VoPo, you name it, all rolled into one chillingly evil package.
About the only honest line he ever utters is, "I'd like to take that cat and..."
The only man worse than he is the Monitor. Because in the Monitor you have Adolf Hitler. "Superior," yet.
And: three cheers for Neutron! If you read my bios, that I've written on all the characters (except the Mutant(s); something's broken there, and I can't build a character page for those guys), you'll know what I say happened to Neutron, and how Cal and Ruth got him back, took him home, and established a long line of Neutrons, just to remind themselves never to trust Nice Government Men, human or no.