The World Beneath our Feet (Part 1).Will Shane is the beacon of justice in Slugterra. But when his enemy, Dr. Blakk, uses a corrupted slug in a duel, Will disappears. As he is sucked into the portal the slug created, Will asks Burpy to find his son Eli and "give him the letter." Years later, fifteen-year-old Eli enters the underground world of Slugterra for the first time. From his father's hideout, he gets gear, a blaster, and a Mecha Beast, which he names "Lucky." He meets Pronto, a proud and knowledgeable molenoid tracker, who convinces Eli to let him join his team. On the road, he meets Beatrice "Trixie" Sting, who saves him from a rogue slugslinger. When Eli enters a tournament to give all nehjdn slugs, he meets her again and discovers that she is shooting a documentary on Slugterra. He also meets a Cave Troll named Kord Zane, who teaches him to duel. In the qualification round of the tournament, Eli duels Shockwire, a powerful slinger who uses only Tazerling slugs. When the two fight, Eli (armed with only Flopper slugs and Burpy) waits for Shockwire to overwork his slugs. When one of the Tazerlings backfires, shocking its slinger, Eli fires Burpy and wins the round. He is allowed to pick a slug from Shockwire's arsenal, but instead asks the slugs if one of them would like to join him, surprising his friends. When one of the Tazerlings agrees, Eli names him Joules and moves on to the next round of the tournament.