Plot
Optimus leads Bumblebee's team into battle against some Decepticons, but end up being helplessly outnumbered and outgunned, causing the entire team to be killed.
Micronus ends the simulated battle, and gloats that Optimus isn't as ready as he had hoped, Micronus heals Optimus' false wounds. Optimus begs to be allowed to return to Earth so he can aid Bumblebee in his mission, and prepare for the upcoming trouble there. Micronus is hesitant but goes to ask the other Primes for their opinions. Once with the others, the Primes flat out refuse, but one of them, Liege Maximo, begins to mock how useless and weak Optimus seems to be, then quietly decides to "help" Optimus with his training too.
Micronus gives Optimus the bad news, but Optimus is still insistent. Micronus simply sets up another test, and creates a recreation of and Earth city, and has Optimus protect some holographic humans from some attacking Decepticons. Whilst Optimus deals with three of the Decepticons, Maximo suddenly enters the simulation, and hides, taking control of the last Decepticon, to make it a lot more powerful.
Optimus is able to defeat the powerful robot, but Micronus is concerned, as he is certain he didn't conjure up something that dangerous for Optimus to fight with. Maximo seems happy that he's messed with the training unnoticed, and plots to cause more mischief.
Micronus opens a portal to Earth for Optimus to watch Bumblebee's team through for a break, whilst he goes to investigate something by himself.
On Earth, the Autobots are playing a football game with Russell, whilst Bumblebee is in the command centre doing some work.
Optimus is happy after seeing his friends again, but it is cut short when Micronus returns and closes the portal. Micronus asks Optimus to go get recharged, whilst he prepares for the next training exercises. However Maximo has been secretly watching them and decides to play with Bumblebee as well...
Back on Earth Liege Maximo sends Bumblebee a fake image of Optimus, and using that image, tells Bumblebee that he has had a change of heart, and has now joined the Decepticons, and that he's coming to attack the Autobots soon. Bumblebee is disturbed, and thinks about how to tell the rest of the team, but Fixit suddenly declares that another Decepticon has appeared on his sensors, Stinkbomb, who is a demolitions expert.
The Autobots head out to Crown City Bridge, where Stinkbomb was detected where they engage the Decepticon, however Bumblebee is distracted when "Optimus" appears in the water beneath them and continues taunting Bumblebee with him switching sides. Sideswipe pushes Bee out of the way as Stinkbomb throws a bomb at him, but ends up being badly injured in the process, unnerving Bumblebee that it was because of him.
Stinkbomb sets off his tail-bomb which allows him to escape, whilst the Autobots try to prevent damage, and get the injured Sideswipe to safety. They head back to the Scrapyard for repairs without their target.
In the Realm of the Primes, Maximo closes his portal to Bumblebee and turns his attention back to Optimus. He finds the Autobot meditating with Micronus, and decides to strike, sending in several small attack-bots to hit him, with Optimus assuming this is a test to keep himself aware at all times. Micronus levitates both of them, and reveals that he didn't create those holograms, and someone else is messing with him, he creates a pyramid for Optimus to wait on top of, whilst he goes to talk to the other Primes about the situation.
Back on Earth, Sideswipe is taken to Fixit for repairs, and Bumblebee seems distracted still. The team grow worried, and due to his lapses in judgement lately and strange attitude, Fixit thinks their leader is suffering with brain rust.
Micronus meets with the other Primes, where he learns that they haven't attacked Optimus, and they then realize that Maximo is missing...
Elsewhere in the realm, Maximo goes after Optimus again, and creates a copy of Bumblebee, but turned evil, and claims that he's there because Earth was destroyed and he was sent to the realm as punishment of some sort. "Bumblebee" attacks Optimus, Optimus is able to defeat the copy, believing it to be a test of Micronus' again. Micronus then returns and tells Optimus that he didn't create the Bumblebee clone, but he thinks Maximo did.
Maximo is annoyed that Micronus is messing with his new "toy" and decides to "play" with Bumblebee again instead.
Bumblebee thinks he's located Stinkbomb on the scanners again, but it turns out to be Maximo's Optimus clone's eyes playing a trick on him. "Optimus" continues with his declarations of evil, but Bee is starting to believe this is all just a trick as well. Bee attempts to destroy the scanner to stop the imposter's messages, but the others stop him, and confront him about his "brain rust" but Bee convinces them that he's fine, and that someone has been sending him fake messages from Optimus. Despite how it sounds, the team respects Bumblebee and believes his story, just in time for them to go after Stinkbomb again.
In the Realm of the Primes, Maximo has a tantrum about how boring the Autobots are. He conjures up a small army of attack-bots, and plans to send them to attack Bumblebee and the others.
Elsewhere, Micronus explains who Maximo is to Optimus, and how despite not really being evil, he is mischievous and will cause problems if he can. Optimus notes that the fake Bumblebee seemed to give up when he didn't believe he was real, which makes Micronus believe he has a chance against Maximo's efforts after all.
On Earth, Bee and the others locate Stinkbomb refuelling himself, and building a new tail-bomb, during the battle however, Bumblebee notices Optimus looking at him evilly again.
Maximo is ready to mess with Bumblebee again, but is suddenly interrupted by Micronus, who confronts his attacks on Optimus and Bumblebee. He tells Maximo to stop with his games, but Maximo ignores him, and continues with his game with Bee.
The Optimus clone on Earth begins screaming at Bee, which catches the notice of everyone in the group, confirming for everyone that Bee hasn't just been seeing and hearing things. The group manage to defeat Stinkbomb, and capture him, essentially ignoring the copy of Optimus, and ruining his schemes.
Back in the realm, Optimus is encountered by "evil" versions of all of Bumblebee's team, claiming that he's failed them again, but he realizes straight away that it's just Maximo's tricks again, and easily destroys them.
Following their defeats, Maximo goes off him a tantrum again, moaning about how unfair it all is. Micronus reappears before Optimus and commends him for his defeat of Maximo, and promises that he will be punished by the other Primes accordingly. He also reveals that Maximo has been messing around with Bumblebee as well, but he managed to fend off the attacks too. He opens a portal so Optimus can tell Bumblebee what was happening.
Back on Earth again Sideswipe has woken up, and everyone is gathered around him. Optimus communicates with them, and assures them that this isn't a trick this time, and the two thank each other for not being deluded by their attackers. Optimus promises to be joining Bumblebee on Earth just as soon as he can, once his trials are over, so they can really be a team again, like the old days...
Characters
Autobot
Optimus Prime - Semi Truck
Bumblebee - Compact Coupe
Strongarm - Police Cruiser
Sideswipe - Sports Car
Grimlock - Tyrannosaurus Rex
Fixit
Drift - Race Car (Mentioned)
Jetstorm - Buzzsaw Deployer (Mentioned)
Slipstream - Buzzsaw Deployer (Mentioned)
Decepticon
Stinkbomb Captured by Team Bee
Megatron - Jet (Mentioned)
Cybertronian
Micronus Prime
Liege Maximo
"Deep Voice" Prime
The Other Primes
Solus Prime (Mentioned)
Human
Denny Clay
Russell Clay
Other
Holograms and Illusions
Primus (Mentioned)
Unicron (Mentioned)
Notes
This story shows a couple more of Optimus' trials in the realm of the Primes, which is what he spent most of season one doing.
This story also shows that Optimus is able to communicate with Bumblebee and the others by utilizing portals in the realm of the Primes. It also shows that other Primes are able to do so too.
Liege Maximo is shown to be one of the Primes in the realm. None of the others (bar Micronus) are identified, but Solus is mentioned in an expressive form, implying that she isn't there for some reason. It's a bit confusing since the last we saw them, Optimus, Maximo and Micronus were all dead and were sent here...so why wasn't Solus?
The only other one of the Primes described here is mentioned as having a deep voice, this could honestly be any of them, but I would guess either Vector Prime or Prima due to him seemingly having the final say on decisions.
Liege Maximo is shown to be able to manipulate his horns to create hard-light holograms or illusions, much like the character he's loosely based on, Loki from Marvel comics.
The main difference between Micronus' holograms and Maximo's seems to be that Maximo's can actually cause physical damage to others, whilst Micronus' are just cosmetic.
Micronus' attitude towards not trusting Maximo is more than likely due to him manipulating Megatronus into killing Solus Prime back in the early years of their existence .
Micronus hints that Optimus may be learning some things from the other Primes as well as him before he leaves the realm, but we haven't been shown that to any extent in the cartoon or comics yet.
Despite him creating a small army and planning to attack Bee's team on Earth, Maximo appears to give up on the idea before the end of the book.