WARNING: This article contains spoilers for Infinity Countdown Prime #1 by Gerry Duggan and Mike Deodato Jr. and The Incredible Hulk #713 by Greg Pak and Greg Land, in stores now.
The Marvel Legacy #1 one-shot by Jason Aaron and Marvel's A-list artists served as a jumping on point for fans and readers. Released in September 2017, the oversized comic introduced new mysteries about Marvel's past, present and future, serving as a launching pad for new adventures.
It propelled Captain America into his cross-country tour of the United States, it showed Thor Odinson a glimpse of the future of Asgard, and it laid the groundwork for a Hulk story called "Return to Planet Hulk," which would unfold in the following months in the The Incredible Hulk comic series by Greg Pak and Greg Land.
The start of this Hulk story came with one of the most curious mysteries from the one-shot: the return of the planet Sakaar, the alien home of the famous "Planet Hulk" storyline by Greg Pak, Carlo Pagulayan and Aaron Lopresti -- a story that partly served to inspire Marvel Studios' Thor: Ragnarok film. Five months later, thanks to the start of the Infinity Countdown crossover event, we now know how the planet miraculously returned.
In Marvel Legacy #1, the Alpha Flight Deep Space Monitoring Station in New Mexico picks up on a strange transmission that originated from the Tayo star system. The message was jumbled by poor reception, but was able to be understood well enough. It was a call for help, a call from Sakaar, pleading for the Green Scar -- the Incredible Hulk -- to return to the planet he once called home.
This was surprising, to say the least, because as far as everyone was concerned, Sakaar had been destroyed. In fact, it was consumed by the Devourer of Worlds, Galactus, back in the son of the Hulk's own series, 2009's Skaar #10 by Greg Pak and Ron Lim. When Amadeus Cho received the signal while in the dead of space in Incredible Hulk #709, he wondered how such a transmission could exist. Proving himself a hero, he didn't hesitate to go through a wormhole, leading him to land on a newly restored planet Sakaar.
Once he found himself on the planet however, Amadeus had no time to solve this mystery. He was thrust into a battle between a cruel tyrant and those he would oppress, a fight that saw him fight aliens, monsters and the Odinson himself. With the Warlord finally defeated in The Incredible Hulk #713, the Hulk leaves the planet behind, now a freed place where its people can prosper -- but with no answers as to Sakaar's mysterious return. Thankfully, readers do find out the answer, in the after-credits page of the issue, in a scene that plunges us into the heart of Sakaar itself.
The page gives us a deeper look into a scene that was first shown in Infinity Countdown Prime #1, which was released on the same day as Hulk #713. In Prime #1, we're taken on a brief visit to Sakaar, where we are informed that the planet exists when it should not. Thanks to the narration, we then learn that the long-missing Time Stone is at the center of the planet's mysterious return.
The definitive answer is given in the after-credits page of The Incredible Hulk #713. There, we see the green Time Stone emerge from the planet's molten lava, with the hand of the Super-Skrull reaching out to grab it for himself. The page's caption reveals that the Time Stone is, in fact, the source of Sakaar's return.
This means that somehow, after the multiversal shake-ups of the Secret Wars event rebooted the universe, and with it the Infinity Stones, the new Time Stone was able to recreate the planet Sakaar from scratch. The Infinity Stones are darn near all-powerful, which means that such a feat shouldn't be put past them. However, it doesn't seem like this is a past version of the planet, because its inhabitants are well aware of the Green Scar. The planet appears to have simply been restored from destruction -- in the present.
What's even more curious is that a future version of Thanos, King Thanos, is seen in possession of a shard of the Time Stone, millions of years in the future. Does this shard belong the Sakaaran Time Stone, or does something happen to the green gem -- omething that will lead to its destruction, and Thanos claiming its remnants for himself?