After forgetting to bring an invention to an academic symposium and being humiliated by his arch-nemesis, Ogden Wernstrom, Professor Farnsworth discovers another invention he attempted to substitute, the "Smell-O-Scope", and uses it to discover than an enormous ball of garbage that was launched into space in the year 2000 is now on a collision course back to Earth. The Planet Express crew are sent to destroy it in space with explosives, but Professor Farnsworth blunders the installation of the bomb's timer and the plan fails. In desperation, Farnsworth proposes they deflect the ball into the Sun by launching another ball of garbage into it. Fry teaches the city how to make garbage, since everyone forgot how to do so over the centuries. The plan succeeds while the new ball flies out into the solar system, and Farnsworth regains his honor.