Captain Man's invisible friend named Brad visits as Henry and Charlotte meet him. Things get worse when Brad wants to become Captain Man's new sidekick by trying to get Henry to quit. Meanwhile, Jasper fixes up Piper's old playhouse in the backyard so that it can be sold in order for Piper to get a Yo-Pro Camera.
Henry and Captain Man must deal with the Spoiler, an annoying new teenage supervillain that finds out the endings of TV shows and movies and tells people about it before they see it. Meanwhile, Piper tries to get into the Man Fans (a Captain Man fan club) led by Paula Makioto and goes through the initiation process with the latest one involving get a selfie with Captain Man.
When a super volcano under Swellview is expected to become active and end the world in two days, Henry, Charlotte, Ray and Schwoz do things they normally wouldn't do in their everyday lives. Meanwhile, Piper is convinced that she is allergic to gluten due to the fact that a lot of her friends and celebrities are allergic to it.
When Henry asks his crush Bianca to be his valentine and go out with him to Club Soda, she rejects his offer since Mitch Bilsky already asked her out. In order to impress Bianca, Schwoz provides Henry an android as a date which can be turned into any human form. Meanwhile, Captain Man reluctantly has a date with Miss Shapen so that she will change Henry's grade on a test that he failed.
In a special crossover with "The Thundermans", Captain Man, Kid Danger, and Phoebe Thunderman, disguised as Mexican wrestlers, infiltrate a secret villain meeting in an underwater lair in Swellview where the villains plan to destroy Swellview's heroes. When they get there however, Phoebe is shocked to see Max as an attendee. The trio needs to defeat the villains while Phoebe tries to convince Max from making a mistake.
When Jasper accidentally gives away a piñata full of killer bees to Piper for her friend's birthday party, Henry and Ray must find a way to sneak in and remove it before harm can be done. They eventually dress up as clowns to infiltrate the house, but things don't exactly go as planned, and the fiñata eventually breaks when Henry finally manages to get it down from the tree.
When Dr. Minyak plans to ruin Double G's worldwide charity concert, Captain Man and Kid Danger join forces with the Game Shakers to defeat Dr. Minyak and keep Double G safe. This is the first 90 minute special of Henry Danger, making it the first episode to be as long as a full length feature film.
After Schwoz’s family reunion causes chaos in the Man Cave, Captain Man reveals a “Superheroes Only” room in the Man Cave for peace and quiet. Jealous, Charlotte, Jasper and Schwoz make a cooler room to show them up. As the gang fights over who gets the better room, things get blown out of proportion.
Henry gets an unexpected visitor claiming to be from the future. When a boy-robot killing machine steps onto the scene, The Gang must find a way to save everyone from an apocalyptic future.
Captain Man's old sidekick and nemesis, Drex, returns from the past with an army of cavemen to finish off Captain Man once and for all. Kid Danger may be the only one who can save Captain Man now.