Dethklok frontman Nathan Explosion wants the band's next album to be the ultimate smash hit. So, to achieve this goal, he decides to have a recording session locked in a Russian nuclear submarine that is moving through the Mariana Trench - the deepest, darkest location in the Earth's crust itself. How brutal is that?!

It's Murderface's birthday, and the rest of the band soon are faced with the difficult task of getting him a present. In fact, he actually ends up hating his party until they finally give him their gift.

The band plays an ancient song which hasn't been heard in thousands of years which unexpectedly awakens a deadly Nordic lake troll and must compose the world's first death metal lullaby to return the beast to its slumber.

Dethklok decides to try their hand at standup comedy in order to avoid burning out on metal. Pickles remains traumatized by a heckler while the rest of the band learns that comedy is all about embracing the hate.

Uncomfortable and embarrassed, Dethklok painfully endures while their parents are in town for a visit. They are at first pissed and doubtful when their parents announce the release of the 'Parents of Dethklok' album, but soon realize the depth of their parents' anger. The guys learn an important lesson: there's nothing more brutal in this world than raising children.

Dethklok has a huge fight on stage, which prompts the record label to hire a performance coach to keep the band together. The band falls in love with therapy for all the wrong reasons.

Pickles decides to go on a reunion tour with his old band, Snakes N' Barrels. The government plots to use a new super-drug to erase Pickles' mind and 'reprogram' him, thereby destroying Dethklok from within.

Mordhouse, the home of Dethklok, opens its gates to the public for the first time in celebration of International Dethfan Day. Will the band and their fans make it through the experience? Dethklok find themselves in potential trouble after two Internet geeks threaten to release the band's exclusive, one-time-only, fan song over the internet unless they give in to their demands.

Upon learning that they've once again earned too much money over the past year, the band tries to "donate" as much as they can to charity as a tax write-off. The guys also unwisely attempt fatherhood and play a landmark concert with the London Philharmonic Orchestra which ends with a killer laser light show.