The Trials of Optimus Prime

The Trials of Optimus Prime is a book that ties into Transformers: Robots in Disguise.

Synopsis
Optimus Prime, Bumblebee, Sideswipe, and Strongarm battle an army of Decepticons in a canyon, with Optimus directing the others. The horde soon proves overwhelming, and despite the addition of Grimlock to the battlefield, the Autobots fall one by one. Both Decepticons and Autobots disappear, another training test for Optimus on the part of Micronus who remains unimpressed with his progress. Though Optimus is anxious to return to Earth, Micronus consults with the other Primes, who believe he is still unprepared. One of their number, Liege Maximo is bored with his eternal existence and decides to amuse himself by introducing new opponents into Optimus's next training session. Though this results in Optimus being more damaged then usual, the Autobot leader keeps it from Micronus for he fears it will impact how long it takes before he can return to Earth.

Micronus allows Optimus to view activities on Earth, where Team Bee is having a game of football with Russell, at least until Grimlock punctures the ball with his teeth. Once the pair go to resume training, Liege Maximo sends a false image of Optimus to Earth, warning Bumblebee of an impending attack. It turns out this is helpful as Fixit soon detects the Decepticon explosives expert Skinkbomb near Crown City Bridge. The team rushes to intercept the new Decepticon, however during the fight, another fake Optimus vision informs Bumblebee that he's renounced being an Autobot and become a Decepticon. Distracted, Bumblebee is only saved from one of Skinkbomb's explosives by Sideswipe, who takes the brunt of the blast. Skinkbomb detaches his tail which unleashes a massive explosion, giving him time to escape, and the Autobots lug their badly-wounded comrade back to base empty-handed.

In the Realm of the Primes, Optimus and Micronus are meditating when Liege Maximo sends more foes after the former. Micronus is able to dissipate the creations, but is puzzled by where they came from. On Earth, as Fixit repairs Sideswipe, he and the rest of the team discuss what distracted Bumblebee, and Fixit concludes it's the early signs of brain rust. Micronus meets with the other Primes again, but when he notices Liege Maximo is missing, quickly realizes who is behind the disruptions to Optimus's training. Maximo's latest trick, an impostor Bumblebee, fails to fool Optimus who swiftly sees through it and is soon informed by Micronus that Liege Maximo is the culprit behind the issues they've been having.

Bumblebee detects Skinkbomb's signal in a quarry outside Crown City, only to again see the false Optimus sent by Maximo. When the rest of the team find him shouting at something they can't see, it only reinforces their suspicion that there's something wrong with their leader, but his insistence that it's some sort of trick that they will overcome helps regain their confidence in him. While Team Bee heads to the quarry, Liege Maximo throws a fit that Bumblebee was able to see through his illusion and prepares to send more foes against Optimus. As Bumblebee's team battles Skinkbomb a second time, Maximo sends an illusion of Optimus, this time to all of them, however they're able to continue their fight. Bumblebee yanks off Skinkbomb's newly-regrown tail, only to discover it's already a live bomb - the Autobots manage to avoid being blown up by it, and Grimlock captures Skinkbomb himself.

Micronus faces down Maximo, while Optimus again faces more false constructs of Team Bee. Forearmed with the knowledge that they're a trick of Liege Maximo's, he easily defeats them. Micronus tells Optimus that Maximo is no longer a threat and faces punishment from the other Primes, and allows Optimus to give some words of encouragement to the real Bumblebee.

Autobots

 * Optimus Prime
 * Strongarm
 * Sideswipe
 * Bumblebee
 * Grimlock
 * Fixit

Decepticons

 * Skinkbomb

Humans

 * Russell Clay
 * Denny Clay

Thirteen

 * Micronus
 * Liege Maximo

Quotes
"How about this: I order you to go keep an eye on the others, and if you happen to have fun in the course of your mission, that's permissible." "Sir, yes, sir!"
 * —Bumblebee tries to encourage Strongarm to relax.

"These Autobots are NO FUN AT ALL! All I ask for in this vast, endless existence is some semblance of joy, and these boring bots are intent on keeping that away from me with their 'teamwork' and 'justice' and 'loyalty'. I can taste the fuel coming back up my intake valve!"
 * —Liege Maximo throws a fit.

"Autobots, it's time to ignite the dynamite!"
 * —Bumblebee

Continuity notes

 * Drift being a part of the team places this book between "One of Our Mini-Cons Is Missing" and "Battlegrounds, Part 1". Drift and his Mini-Cons are off on a scouting mission, much as he was in "Bumblebee Versus Scuzzard".
 * Optimus refers to his victories over Megatron and Unicron, which took place back at the end of Transformers: Prime.

Real-world references

 * Skinkbomb likes making pop culture references. "You get an explosive! You get an explosive!" is a reference to a 2004 Oprah Winfrey show in which she gave away cars to her entire audience, "Hasta la vista, babies!" is a paraphrase of a line from Terminator 2, and "Exit, stage left" is a stage direction popularized by cartoon character Snagglepuss.