Having finished with Kur, the Sphinx turns to seek counsel with his prophet, Sayge. Sayge tells the Sphinx that he, despite his great power, is not a god. The Sphinx argues that he is immortal and must be a god. The prophet turns his "face" to the Sphinx and shows his master his true soul. The possessor of the Ka Stone cringes in fear and admits that Sayge is right. Although he is immortal, the Sphinx seeks the hidden knowledge to end his 5,000 year old life.

Back at Harry S. Truman High School, Ginger Jaye asks her friend, Bernie Dillon, to help her find out what's wrong with her boyfriend, Rich Rider. Bernie thinks that since Rich failed his midterms, he is too embarassed to go to school. Ginger feels that it's more than that. Bernie is Rich's best friend and he decides that he is going to find out why Rich has disappeared.

Back at the Sphinx's Pyramid Of Knowledge, Powerhouse and Nova are waiting to be mind-probed by the Sphinx. The Sphinx states that he's tapping the 'pineal', one of the body's Seven Centers of Energy. The pineal holds all conscious and unconscious memories. If the Sphinx finds the knowledge he seeks, he will seize the energy and end his centuries-long life. The Egyptian villain begins with Nova. To his utter amazement, the Sphinx learns that Nova holds the long-sought knowledge! Unfortunately, extracting the information would kill Nova long before the Sphinx could gain it. Sayge appears to tells his master that the same Nova Force that gave Rich Rider his powers also gave him the forbidden knowledge. Nova is unaware that he possesses "one of the four secrets of the universe" and, thus, cannot share it.

The Sphinx decides that since it is Nova that hides the secret, then Rich Rider will no longer be Nova! Using the Ka Stone, the villain removes Rich's knowledge of the Nova powers from him. With no memory of his powers, the Sphinx believes that Rich's mind will eventually become less guarded. At the right time, the forbidden knowledge will be easy to remove from him. The villain turns his attention to Powerhouse. Since Powerhouse is no longer needed, the Sphinx wipes the memory of Nova's foe clean and teleports him to London.

Back at HST High School, Rich Rider finds that he is late for class and is sent to the guidance counselor's office. An hour later, Rich and Ginger run into the school bully, Mike Burley. Rich and Mike exchange punches, but without the Nova powers, Rich is knocked down. Ginger assures Rich that he'll be all right and that he looks a lot better since the accident. Rich is puzzled by her reference to an "accident". As they eat lunch with Bernie and their other friend, Roger "Caps" Cooper, they begin to talk about their upcoming field trip. The group is scheduled to tour WXYZ-TV. Bernie mentions that their original tour was cancelled after Rich's accident. The second mention of the "accident" begins to trigger Rich's memory. The accident they're referring to was when Rich received the Nova Force from Rhomann Dey.

Afer school, Rich returns home and talks to his father about his failing grades. Charles Rider tells his son that his brother, Rich's uncle, will begin tutoring him next week. Rich's father leaves to talk to the bank about their mortgage. Without his principal's job, the Riders may lose their home.

Later, Rich and his friends are touring the station when they notice Star Trek playing on a monitor. The sight of the starship Enterprise returns all of Rich's memories and he is Nova once more! The Sphinx appears and tells Nova that he has come for the hidden knowledge. Nova and the Sphinx engage in a fierce and furious battle with Nova refusing to give in! The Sphinx is stunned by Nova's will and courage. Nova tells the Sphinx that he'll die before he gives him the knowledge he seeks. The Human Rocket falls unconscious. The Sphinx admits his respect for Nova and that he is "more of a man than I have seen in many a century". The Dreaded One departs and tells Nova that he'll be watching him. He also states that he'll return and the knowledge will be his!