Scientist Ozma Furbanna asks for help to stop the poaching of native animals on the planet Karn. Mistaking him for a rare species, the poachers kidnap Booster.

XL has found that the primary difference between he and XR is that XR has a component called an AFD, so he kidnaps XR and removes his AFD.

When Buzz is pulled into a black hole, Zurg tricks him into revealing all of his secrets in his latest attempt to destroy Star Command.

Compu-klerm Co. brainwashes Buzz into thinking that he is an office clerk. Buzz's combat skills are downloaded into the Klerm Slambots, which Team Lightyear then have to fight to save Buzz.

Zurg mutates Jo-Ad vegetables w/ Transdibulator. Team Lightyear goes to Jo-Ad to investigate the problem. Booster's childhood pal, Buster, was lured into helping Zurg w/ the promise of glory and power (he had been jealous of Booster getting to join Star Command while he was stuck back home on the farm).

While fighting NOS-4-A2 with Buzz, Space Ranger Ty Parsec gets bitten by an energy vampire and he turns into the Wirewolf.

Zurg hits Mira & Buzz with gas that melts & melds them into a shoggoth-like creature, then sends them on their way back to Star Command; Mira/Buzz accidentally infect all of Star Command upon their return.

After investigating a rash of robo-homocides, Team Lightyear discover that NOS-4-A2's loose on TradeWorld with a self-appointed ""slayer"" on his floating tail -- Savy SL-2, a human orphan that was adopted by a robot couple. NOS-4-A2 had ""vamped"" her adoptive parents, so she decided to step in as a vigilante vampire-robot-slayer (...a la Buffy...). With her assistance, they hunt down NOS-4-A2, fight his horde of enslaved robots, and defeat him, freeing those robots that were in the grip of his dark forces (...including XR who, as usual, was an easy mark for NOS-4-A2...).

Zurg stumbles upon an alternate dimension where Buzz is evil (...possibly more evil than Zurg, himself...) and has taken over the universe. Zurg has Buzz, the evil one, capture Buzz, the good one, and trap him in the other dimension while they capture Star Command. Buzz's teammates (the good Buzz's, that is) venture into Zurg's Dreadnaught, thinking Buzz has gone insane, but, alas, are captured. Meanwhile, Buzz (the good one) is chased around by the alternate Mira and Booster (the bad ones). He gets a reprieve from the alternate Nebula (who isn't all that bad), who knows that Evil Buzz is working with Zurg. They team up in order to stop the bad guys. Team Lightyear is rescued, Star Command is saved, the Dreadnaught blows up, Zurg and his minions escape, and Evil Buzz is left floating out in space, ready for his revenge in ""Sunquake""...

After pilfering samples of Team Lightyear's DNA with mosquito-esque micro-hornets, Zurg clones Team Lightyear; in his rush, he removes them from the maturation tanks before they have a chance to grow up into adults (...as an example of his hurried-ness, he initially planed to instill them with an ""Evil Level"" up in the thousands, but upon realizing that he himself has an ""Evil Level"" of a little over a dozen, he only gives them a level a little under his own...), so Team Lightyear has to deal with evil little kid versions of themselves named Zzub, Feara, and Blister (...after a lot of whining about not having a robot of their own, they get an evil version of XR called ""X-Treme""...). When the eventually realize that due to being clones, the Evil Li'l Team Lightyear has the same character flaws as themselves, Team Lightyear manages to use their ""flaws"" as advantages and win the fight. As a joke tag-line, Zurg attempts the cloning process again at the end of the episode

Team Lightyear receives a call from Jo-Ad while in the early phase of an investigative mission (involving a series of thefts); Booster's family is letting Booster know that the bunzel harvest (the primary crop on Jo-Ad, which resembles eggplant) is due. When Booster claims that his duty to the Space Rangers supersedes his farming history, his Grandfather reminds him of the legendary ""Bunzel Fever"", that strikes down any native of Jo-Ad that isn't involved in the bunzel harvest. Booster dismisses the legend and eschews the harvest. When it turns out that the legend isn't a myth, Booster goes through a ""pon-far""-type thing, that is marked by him ""hulking out"" into a large, bellicose form that is determined to harvest bunzels, or anything bunzel-esque (...and since this transformation is also marked by him having spells of mistaking anything roughly ovoid for a bunzel, this gets fairly hazardous for anyone who is rotund and/or in a space ranger suit, XR, and Team Lightyear's ship

Zurg steals a remote trash compactor, compacts 42, and then compresses Capital Planet's sun in order to form a black hole.

Zurg tries to take over the planet Roswell, in order to set up a partner planet to Planet Z. Becky contacts Booster, and Team Lightyear shows up to defeat Zurg and save the day. The climactic battle between Zurg and Buzz takes place in the reactor chamber that is powering his self-constructing re-formation of Roswell; when they begin fencing with glowing reactor rods, and when Zurg attempts to throw Buzz off guard by claiming to be his father, the Star Wars references fly fast and furious. The self-constructing machine is thrown into reverse, Roswell is saved, and Zurg is defeated.

After being bitten by NOS-4-A2 on the mysterious planet of Canis Lupus, Ranger Ty Parsec is transformed into a Wirewolf (...imagine a form of lycanthropy blended with either Star Trek's Borg techno-virus, or with Transformers' Key to Vector Sigma...) [this whole bit is shown in summary, as if it were reminding us of an earlier episode...except there IS no earlier episode about this as far as I can tell]. Even though the transformation only takes place when on or near Canis Lupus, Commander Nebula decides to boot Parsec from the Space Rangers for his own, and everyone else's, good. While this meeting is wrapping up, NOS-4-A2 and XL show up. They have a chunk of Canis Lupus, that causes Parsec to re-transform into a Wirewolf, and they kidnap the en-cursed Parsec. [...the ""Monster""-bit in the title refers to how Parsec is pretty much a robotic werewolf, XL is pretty much a robotic Frankenstein's monster, and NOS-4-A2 is a robotic vampire...] With Parsec

Ship 42 scopes out area where ships have vanished. Upon scanning the planet, they detect large amounts of technology on the planet, but upon landing it seems quite barren. Flying manta-like shriekers attack Team Lightyear's technology, leaving them stranded and defenseless. Roaming the countryside, they encounter a man named Flint who runs a town of castaways from spaceship-wrecks. Upon investigation, Flint turns out to be a renegade work robot (gamma series construction robot), who built the robotic shriekers in order to strand organics on the planet, so that he could order THEM around as revenge for his time spent in forced labor (...as a stock-boy...). Team Lightyear shut down the subterranean shrieker construction plant that Flint had built, and defeat Flint, freeing the hapless castaways.

When Booster is kidnapped by the Raenoks, in order to conduct a prisoner trade for Varg (XR is sent to guard Varg, who quickly escapes and takes XR to Raenok), Buzz & Mira fly off to save him w/ a newly developed cloaking device that can render 42 and/or its crew invisible. While attempting to sneak into the Raenok prison, Mira and Buzz spot Booster's folks, who heard about their son's capture and decided to attempt to save him. This allows the invisible Mira & Buzz to get through the first line of defense, while the capture of the Munchauser's provides a distraction. When they're attempting to figure out how to get through the second line of defense, Becky and her father, the Sheriff from Roswell, arrive (having also heard the news of Booster's capture). The capture of the Roswelleans provides yet another distraction. Finally, the LGMs also decide to help, which almost allows for Mira & Buzz to free Booster (...and XR, and Booster's parents, and the Roswelleans...), but they end

The Galactic Alliance President is about to sign a ""historic peace initiative"" in the Senate chamber, when Commander Nebula narrowly saves her from a sniper's blast. Thousands of witnesses see Buzz fleeing the scene. The next morning, Buzz gets his morning paper and is about to do the crossword, when a SWAT team breaks in. (Buzz is completely cool, even giving them tips on their technique. Then they grab him.) We learn that the Gargantian Militants have constructed new robot-vehicles similar to the Flash Fleming android they used in earlier episode Inside Job. Now, however, they have ones duplicating Buzz and others.

First, the Gargantians pose as a doctor to give Buzz a negative psych evaluation. Then, they pose as the judge as Buzz's trial to insure he is convicted and sentenced to life in prison. Finally, they take a space aboard the prison transport as a convict and try to get Buzz. This last effort causes a crash and Buzz escapes.

A Buzz from 150 years in the future arrives to prevent Mira from being killed.

Due to a diplomatic faux pas with the Porcelon Ambassadorial Delegates, Team Lightyear is delegated to traffic duty.

While on an archeological expedition studying Planet X, a group of LGMs stumble upon the resting place of an ancient powerful being called Natron.