The Monorail Bombing occured during the beginning of the 2013 arc, and was an act of sabotage against Ta-Koro's monorail system by the mercenary Akriin.
Vo-Toa Akriin, a mercenary, was hired by an Onu-Matoran to damage the Ta-Koro monorail system using a remote device and photothermic (or Stralix) powder. He traveled to Ta-Koro, laid the device, and pulled the trigger after leaving the area for Ko-Koro and payment.
- Bomb planted and detonated by Akriin. Akriin then flees to Ko-Koro and hides.
- Ta-Koro Guard's investigative division appears on the scene, using a kanohi of psychometry to luckily gain a glimpse of the saboteur.
- Akiri Jaller receives the briefing documents and summons Angelus and Oreius. The two toa of fire are sent on a mission to retrieve the bomber. Angelus brings along Kino Iho and Liacada, a former Bad Company member and Guard consultant, to round the squad out into a party of four.
- Traveling to Ko-Koro the group finds Akriin sleeping in the snow. He surrenders willingly and is taken to Ta-Koro.
- In a special room, Akriin is questioned by Akiri Jaller but refuses any attempts for peaceful divulsion of his employer, stating he should die for the good of all. In a cold fury Jaller lets Kino Iho take over the interrogation and leaves.
The investigation of the Monorail bombing is still ongoing for Ta-Koro. However, after the Akiri Summit and the renewal of peace between the Koros, little has happened.