Professor Farnsworth receives word from Mars University that they are revoking his professorship. When he arrives before the university's professors, he reveals all their secrets until he realises it was his 150th birthday party. After everyone talks about how great he is, Farnsworth becomes concerned with his own mortality. He decides he needs to name a successor. The Planet Express staff expects one of them will be named, including Fry, but Farnsworth reveals that his successor will be a 12-year-old clone of himself, Cubert Farnsworth.
Cubert decides that being an inventor is not an appealing career choice. He makes cutting remarks about the Professor and his inventions, which include a time travel machine and a translator which turns words into an incomprehensible, dead language (French, despite this being used in the show before). A depressed professor makes a recording over Bender's soap operas telling his crew that he has been lying about his age; he is actually 160, the age when robots from the Sunset Squad take people away, never to be seen again. Under cover of an overly-dramatic thunderstorm, a Grim Reaper-like hooded robot arrives, and takes the professor away even when he says good-bye to everything in sight.
The crew set off to rescue the professor, and find the Near-Death Star, the Sunset Squad's base of operations. The crew sneak in with Fry dressed up as the professor (who apparently escaped) with Cubert on his back posing as a hump to make him look "old". They even brought a huge jar of Cubert's blood just in case. They locate the professor, who is unconscious and hooked to a life-support system. The robots discover the crew who then race back to the Planet Express Ship, Professor Farnsworth in tow.
As they reach the landing pad Cubert is knocked unconscious, but they make it onto the ship in one piece. When the ship takes off, the robots open fire, damaging the engines. A reawakened Cubert announces that he knows how to fix the engines, and the crew make their escape. It is revealed the dark matter engines don't move the ship, but instead move the universe, allowing the ship to go faster than the speed of light. Safely back on Earth, Cubert tells the professor that he has decided to follow in his footsteps.