Three years later, it's time for Cell to appear, and Trunks is going through the motions of going back in time. Cell wants to know how his victim knows this. This time, Trunks is going to finish things. He blows Cell up into the air, and the two of them go out to an unpopulated area outside the city. They brag a bit, then attack.
Cell swears and dies.
Trunks has won, and he thanks Gokuu and friends. The narration box simply says that the living Trunks has brought peace to his future timeline.