Krill and Wyatt were exceptional students in the Plumber Academy. Following their final combat training session, Max Tennyson pulled them aside to say that he was going to look at the intermediate curriculum to see if it was even necessary for them - if not then he'd bump them up to advanced-level training.
By now, Krill and Wyatt were accomplished Plumbers and had achieved elite rank. They went with two other men to rescue family members of one of the Magisters from an abandoned factory in Bellwood. However, the hostages were placed on a pressure pad, and removing them triggered turrets to shoot everyone in the room except Krill and Wyatt.
Krill and Wyatt received texts from the anonymous perpetrator that led them to a TV screen - a distorted and modified voice explained to them how he is interested in their work - he uses their parents' personal info to blackmail them into becoming his personal assassins. Their first mission was to kill Tetramand warlord Kors Rhoom, who they found and killed on Morotesi, disguising it as a mining accident.
Following an assassination in outer Bellwood, Krill and Wyatt were contacted by their employer for their next target: Ben Tennyson.
Krill called Kevin on his phone and asked him where Ben was - Kevin refused, but Krill had placed a bomb in his phone beforehand in an attempt to get him out of the way - Kevin got rid of the phone before the bomb could harm him.
Krill and Wyatt held Ben's parents hostage, but were attacked by Kevin. Ben later came to assist them, followed by Gwen. They engaged in a long, brutal fight that they purposely moved out of the neighborhood and under a bridge leading to the central city. Ben used Big Chill to take them down.
Max called Ben to inform Ben who Krill and Wyatt were following his discovery of the truth. Krill and Wyatt become tense after finally hearing Max's voice again, and tell Ben and the others about how they were recruited. The man then texts them asking them where they are - Ben goes ahead and threatens him, but doesn't realize that the man has the brothers' parents hostage. He subtly orders them to commit suicide, which they comply with to Ben's, Gwen's, Kevin's, and later Max's horror.
Their parents, however, are released and sent to the Plumbers' space headquarters with a note from the employer promising Max they will meet again. Max crushes the note in anger.