Bob's attention turns to the escalating danger in the skies over Mexico city, where a massive brown cloud has begun to combine with the toxic emissions from a nearby volcano. The new mixture could rain sulfuric acid down on the city and Bob must try to convince the Mexican officials of the gravity of the situation before all of Mexico City is destroyed.
Homeland Security is monitoring two scientists in Chicago who they believe are a threat to the US President. After taking samples from their lab, David feels the investigation is unwarranted and the two are set free.
Owen shows up at David's office looking for a place to stay.