The End - Part 2 is the 12th episode of season 4.
The episode starts with a brief recap of The End - Part 1. Raven has become the portal by which her demonic father Trigon enters the realm and puts an end to the Earth. He unleashes a mighty wave of destruction across the planet turning oceans to lava and the sky to a blood red, buildings and edifices are destroyed, and everyone is turned to stone.
Somewhere in the ruined streets of Jump City, a small barrier created by Raven gives out and Robin is shown lying underneath. He comes to and stares speechlessly at the ravaged landscape. He sees the innocent people frozen by Trigon's wrath and frets over how he could have done something more to stop this. He spots a big, red-eyed raven alighted on a nearby stone slab, wondering if it is his lost friend. The bird takes off and Robin follows, calling after it. The raven flies higher and lands on top of a big skyscraper. Robin climbs it and finds Beast Boy, Starfire, and Cyborg at the top, alive and well but disheartened. They deduce that Raven used her powers to ensure that they survived the apocalypse. Cyborg wonders what the use of that was since they were the only ones who lived and there is nothing left. Robin doesn't give up hope and declares that they will keep fighting in honor of their friend Raven. They join hands in promise and as they do so there is a sudden burst of telekinetic energy among them. They figure that Raven must have left them with some of her powers and it is at its strongest when they are joined together.
Trigon has made Titans Tower his throne. He sits silently biding his power and growing bigger. Without warning, the Titans attack, but they fail to even make him flinch. Starfire explains how Raven's powers are controlled by emotion and they join hands preparing to hit Trigon with everything they have. They all shout out Raven's incantation and a massive beam of telekinetic energy hits Trigon full on. He seems to be hurt by the beam, but then just smiles and says that not even a "farewell blessing" from his daughter can hurt him. He mutters "Begone" and blasts them with his eye beams back to the ruined site of the old library.
They all get up painfully, now even more demoralized than before. Robin looks down the hole that leads to the inner bowels of the library and ponders over how it doesn't feel as though Raven is truly gone. A voice says "That's because she isn't" and Slade emerges from the darkness. The Titans attack him on sight, but he makes no move to retaliate. He says he hasn't come to fight, but to help and that he knows a way Raven can be saved. The Titans emphatically refuse his offer out of disbelief. Slade tells them that they can think of him as they will, but assures them that what Trigon did to the Earth, Slade would never wish. Cyborg states, "It's a little late for I'm sorry". Slade tells Cyborg not to mistake his offer for regret. He's only helping them because it suits him. Starfire then says that Raven was destroyed when she became the portal. Slade says that the part of Raven's existance as an interdimensional portal is complete, but another part lives on elsewhere. The Titans ask him where, but he offers to show only one of them the way on account of Trigon being all-seeing and will therefore need to be distracted while Raven is searched for. Robin volunteers to accompany Slade no matter how slim the chances of finding Raven may be. Slade gives the other three Titans a Ring of Azar, a ring that extends a certain degree of protection from Tigon's power on the wearer. As Robin says goodbye the others promise to hit Trigon with everything they have and Starfire shares a heartfelt embrace with him. Slade remarks on the sentimentality of their goodbyes and goes to the hole leading to the underground. Robin vows to bring Raven back and departs with Slade into the darkness.
They walk along the path until they come to a huge door with a Mark of Scath on it. As they pass through, Slade warns Robin that if they are successful, Robin may not like what he finds. Robin says he'll take his chances. They proceed to pilot a boat down a river of lava.
Meanwhile, the Titans get Trigon's attention by having Beast Boy fly into his ear as a hummingbird and then turn into a blue whale. As the Titans stand before him, he breathes a blast of fire on them, but the Ring of Azar that Starfire is wearing proves useful. Trigon is daunted by this and notes Slade's betrayal but he still refuses to expend the energy to annihilate the Titans. Using his powers he makes evil clones out of each of the Titans and pits them against each other, each against his or her own clone.
As they go down the river, Robin asks Slade why he sold out the world to Trigon. Slade tells Robin that with or without his help, nothing could stop this. But Robin still says that Slade had a role, and like everything else he has ever done, it has made people suffer. Slade simply replies that it's what he does best. They are then ambushed by an army of Trigon's fire-borne minions. By fighting together, the two adversaries swiftly repulse the onslaught. One of the last of the fiery assailants knocks Slade's mask off and Robin is taken aback when he sees Slade's face is just a bare skull with a single red eye.Slade retrieves his mask and declares this condition to be temporary and suggests they continue on. Robin refuses to go further until he gets some answers. Slade says that Terra's attack should have been his end but Trigon saved him and made a deal that Slade would bring him Raven and he will return Slade his humanity and grant him enhanced powers in the meantime. Slade finishes his story with Trigon's reneging on the deal and says he is only doing this to get back his own flesh and blood.
Above ground, the other Titans are engaged in grueling battle with their evil selves. Nega Beast Boy matches Beast Boy form for form, but Beast Boy holds his own quite well. Nega Cyborg has knowledge of Cyborg's weak points and uses them to full advantage. Starfire is evenly matched with her alternate form. The clones also display knowledge of each Titan's inner feelings and use this to taunt them. Nega Cyborg taunts Cyborg with the death of his mother, Nega Starfire says that when she wins Robin will be hers, and Nega Beast Boy reminds Beast Boy of Terra's duplicity.
At this point in the journey, Robin and Slade come to a fork in the road. Slade points Robin down one path and says they must part company as he goes down another. Robin expresses his surprise that Slade kept his word, but he assures him that the next time they meet, it will be as enemies just as before. Slade doesn't expect anything different.
Robin's path leads him to an immense cavern with a ruined temple in the center. As Robin searches the ruins he comes across a young girl with a white robe who looks exactly like Raven, but she is no more than nine years old. As the child looks up at Robin she meekly asks, "Who are you?"
- Robin: I thought we had a deal!
Slade: Old habits die hard.
- Slade: You must be overjoyed to see me like this, Robin. Desperate, weak, vulnerable.
Robin: I'm here to save Raven, not pity you.
- Nega Beast Boy: What's the matter? Had enough? No wonder Terra dumped you!
- Trigon:(After passing through the portal) THE EARTH IS MINE!!!!!!!