Planet 0259-S was a planet owned by Thanos that he intended he and the Black Order would retire to after they'd brought balance to the universe. Thanos spoke of this to Nebula at length while she had her cybernetics fitted.
In 2018, after Thanos had achieved his lifetime goal of killing half of all life in the universe, via the power of the Infinity Stones, he used the Space Stone to teleport himself to the Garden, where he settled while smiling contentedly at the sunrise.
Three weeks later following the Snap, Thanos used the Infinity Stones to destroy themselves in order to avoid being tempted to use their power for personal gain while also knowing that the Avengers would attempt to reverse the Snap with them, though this ended up wounding him badly and scarring him as well as permanently ruining the already damaged Infinity Gauntlet. This action resulted in the Gauntlet being fused to his hand forever. Two days later, while at his farm making a stew from his crops, the Avengers tracked him down using information garnered from Nebula and showed up as part of an ambush, with Thor cutting off his left arm preemptively with the Stormbreaker. However, this was a futile effort as, to the team's horror, Thanos revealed what he had done to the stones two days before. Though the Avengers initially thought him to be lying, Nebula confirmed that Thanos was not a liar. Touched, Thanos thanked his last daughter, even admitting that he'd been too harsh with her before an enraged Thor cut off his head in retaliation. Defeated, the Avengers left the planet, leaving Thanos' corpse behind.
- In the comics, at the end of the Infinity Gauntlet story-arc, Thanos fakes his own death and retires on a distant planet to be a farmer.
Behind the Scenes
- Joe Russo coined the name of Titan II during a Q&A with Collider. The name was used also in the script of Avengers: Endgame but it was never used for the planet onscreen nor in Avengers: Infinity War tie-in merchandise. In Avengers: Endgame, it was officially referred to as "The Garden" and as "Planet 0259-S."