Earl gets irate when Mrs. Snodgrass praises Billy and Marcus' model space shuttle as the most ambitious that she's ever seen. Earl hauls out his old model of the solar system and expands it to life size to remind her of his great work. But the planets are all out of order and turn the school into a massive galaxy that's going to hurtle the earth right into the sun! Billy tries to realign the solar system by knocking planets into their proper places with their space shuttle, but he takes short cuts which threaten to ruin the mission. Marcus reins in Billy's rushed effort and calmly figures out a way to divert the sun, sending it crashing into Earl's boiler room! Marcus saves the school, and Billy learns the value of careful preparation and planning.

Marcus' stamp collection is of no interest at all to his friends. However, one of the stamps catches their eye. Marcus' 1918 ""Curtiss Jenny Inverted"" stamp, one of the rarest in the world, is worth over a million dollars! The gang smothers Marcus with attention, but it's clear that they're only interested in his stamp for the money. Earl, meanwhile, wants Marcus' stamp for his own stamp collection! Morphing the school into a stamp factory circa 1918, Earl tries to steal the precious postage right after it's made! The kids prevent Earl from stealing the stamp and changing history, but not before learning that greed should never be a motivation for appreciating something.