After his rest, Mannie receives the news from Earth that people indeed did ignore the warnings and showed up to see the boom—fifty thousand people are dead in North America. Terrans are calling for Luna blood.
The Tycho Under evacuation isn't going well either, as people refuse to leave. Prof and Mannie have a small tiff about this, but Prof stands firm that they will not use coercion. They decide to warn everybody and keep guards posted.
The bombardments continue as planned, but people wise up and don't try to sightsee the devastation.
At the War Cabinet meeting, each member has a different opinion about how to deal with the situation. After some chit and a bit of chat, they decide to carry out the bombardment.
Mike wants Mannie to go to his idiot son so Mannie can properly program it if things go wrong.
Mannie calls Prof to see what he thinks. Prof informs him that whether Luna City is destroyed or not, Mike loses his radar or even dies: "Mike still gives Luna even chances if Little David's Sling can operate—and you are there to operate it" (27.89). So, no pressure.
Wyoh and Stu meet Mannie at Mike's son (a.k.a. a less awesome computer) with luggage and everything they'll need. They're in it for the long haul.