The Ultimate Team No More?

An argument over who pulls the team's weight causes Agumon and Marcus to separate, but when a Digimon attacks the city's electrical grid, they'll have to overcome their differences.

Synopsis
After winning a fight with a Tortomon, Marcus and Agumon rejoice saying that their ultimate team always wins! While having dinner at Marcus's house, Marcus and Agumon have a fight over the last piece of Fried Egg and split up. Agumon returns into his Digivice and gets back to DATS. The people try to make Agumon apologize but it was of no use. Meanwhile, Marcus thinks that he can win any fight without anyone's help.

Suddenly, an Elecmon appears, in ontop of a broken traffic light. The fellow members of DATS continue to try to get Agumon out of his digivice but to no avail. Meanwhile, Marcus runs into some bullies and easily defeats them despite it being 1 against 5. The fisherman that first gave Marcus his digivice appears as a fortune teller and explains to Marcus that he needs Agumon, but Marcus ignores it and walks off. The Elecmon appears again and begins to attack while the DATS members try to trace Marcus but can't contact him. Marcus gives chase to the Elecmon after saving a little girl from almost getting hit by a truck and calls to Agumon, but remembers that they are not partners anymore.

After absorbing energy from the old Broadcast Tower, the Elecmon digivolves to BlackGarurumon. Thomas and Yoshi soon arrive and Gaomon and Lalamon digivolve to Gaogamon and Sunflowmon to fight back, but Marcus charges in anyway. Marcus jumps on BlackGarurumon's back and rides him until they come to the End of the Line, literally, a railroad still under construction. He fights again but is close to the verge of losing. All his happy memories about he and Agumon come back to him and he feels sad at that but realizes that it's too late to apologize. While holding BlackGarurumon with his charged DNA, in sadness, he calls out to Agumon and to his surprise, Agumon comes and saves him. They both reconcile and Agumon digivolves to GeoGreymon. GeoGryemon delivers a Mega Flame and BlackGarurumon unleashes a Howling Blaster, and the attacks collide. Marcus gives some words of encouragement and GeoGreymon is able to defeat Black Garurumon. They both realize that together, they make the ultimate team again.