The armored billionaire shows the surprised teenager his room. As Nova looks at his hovering bed, Iron Man explains that the Invisible Woman had insisted their headquarters be a blend of technology and nature including a large number of plants. Suddenly, Rich calls the team over as something strange has happened in his quarters. The trees in Nova's room have been manipulated into forming a message from someone who wants to come inside the headquarters!

The Avengers race outside to face the person responsible and find themselves facing Plant Man. Before the team can attack, Plant Man quickly tells them he does not want to fight and needs their help. He explains that the plants told him about the new headquarters and the person he is seeking refuge from is the Silver Surfer. It appears the cosmic hero has become extremely violent and began attacking Plant Man on his farm for no reason. The Avengers are hesitant to believe the super-villain but the Surfer's odd behavior is consistent with the incidents they've been tracking.

Nova tells Captain America and Invisible Woman that he would prefer to fight anyone other than the Silver Surfer because he's so powerful. The star-spangled hero explains that they can't choose who to protect and who to protect them from. Rich says he understands but isn't looking forward to the fight. The Avengers tell Plant Man they need proof of the Surfer's aggressive attitude. Plant Man points out that won't take long as the cosmic attacker has been unstopping in his pursuit.

The Invisible Woman tells him to create a duplicate of himself from the nearby plant life. She wants to witness the Surfer's actions when he arrives. Sue Storm also instructs the Black Widow to take Plant Man down to an emergency underground bunker which may be able to slow down the Surfer from getting to his victim. Nova is still worried about the upcoming battle until Captain America explain that the Avengers have their own firepower including Thor.

Down in the bunker, Black Widow places the vegetation villain into a vault and closes the door. Once alone, she opens a secret communication with Dr. Reed Richards to give him a status report. She tells Reed that Sue is not showing any signs of change in her health. The leader of the Fantastic Four mysteriously says that he wishes the events yet to come were over. He also points out that this event is the reason he asked her to join the Avengers. The Black Widow reminds Dr. Richards that he didn't ask her and she will never forget what he did. She then cuts off her communications.

Miles away, the Vision appears at the home of Diablo. The super-villain is not surprised to see the Avenger and claims to know that he has come seeking answers about human emotions. As they discuss the android's quest to understand emotional states he does not possess, the two come across a young woman laying on a stone table. Diablo introduces her as Avril, his fellow student and love of his life for hundreds of years. He explains the two of them had studied together under a talented mentor. Diablo studied the art of transmutation while Avril searched for the answers to eternal life.

Avril was successful in her goal but was also driven insane by the process. She wrote her research into a book called the Voynich Manuscript but chose to write it in a secret code. Diablo understood it would take someone who was also insane to decode the book. He then began his own search for eternal life in order to restore Avril's mind. To further protect her, Diablo placed Avril into a sleep state.

Meanwhile, back in Manhattan, the Silver Surfer has found the duplicate of Plant Man and quickly destroys it! The Avengers respond as Captain America orders Thor to unleash his hammer's full power. A massive lightning bolt cuts through the sky and strikes the Silver Surfer and sends him crashing through the ground! Cap tells Nova to lead the Surfer away from them so they can get Plant Man to another safe location. Rich takes off and believes that nothing can catch him once he is going full speed. The confident teenager suddenly finds himself grabbed by the Silver Surfer and thrown through a nearby building!

Back at Diablo's lab, the Vision informs the scientist that he has read and understands the code used in the Voynich Manuscript. The android Avenger explains the code and offers to download the translation to Diablo's computer. Before he can start the process, the Vision's communicator begins beeping and a holographic image from Iron Man appears. After hearing the frantic message, the android requests some alchemical equipment and the process to alter emotional states from Diablo. The super-villain agrees to help.

Back at Avengers Mansion, the Silver Surfer and Thor continue a fierce and powerful battle in the streets. The silver foe is knocked to the ground by the Asgardian hero. However, Thor does not feel it is honorable to hit an enemy after he is down. The Surfer quickly counters by smashing his board into the unsuspecting thunder god. The Invisible Woman angrily attacks their enemy with a barrage of invisible spheres. The Silver Surfer immediately blasts Sue Storm unconscious.

As Captain America unsuccessfully attempts to talk reasonably with the Surfer, Nova flies in at full speed and punches their attacker with fury! Rich tells the star-spangled hero to get everyone to safety as he, along with Thor, will hold off the Silver Surfer. As they attempt to leave, Sue turns to find the Vision floating in front of her.

The artificial Avenger quickly breaks a lab flask he brought from Diablo's lab near the Silver Surfer. The chemicals inside quickly change the Surfer's behavior back to its normal calm state. The Vision explains that based on the available evidence, the Silver Surfer had been driven to his mad state by the pollen given off unintentionally by Plant Man. Once he knew the cause, the android was able to create an antidote. To prevent another incident, Plant Man quickly alters his organic structure to prevent the creation of more pollen.

The Silver Surfer uses the power cosmic to undo all the damage caused by their massive battle and apologizes to Plant Man for the attack. Plant Man accepts and turns to leave the scene. Before the villain can go, Nova asks Plant Man for a favor. Rich reveals that he is terrible with plants so Plant Man agrees to check on the plants in his room every once in awhile.