WARNING: The following article contains major spoilers for Avengers: Infinity War, in theaters now.
The opening moments of Avengers: Infinity War delivers what audience has feared since the mid-credits scene of 2017's Thor: Ragnarok, with the Sakaarian vessel transporting Thor, Loki and the Asgardian refugees under assault by Thanos and the Black Order. After acquiring the Space Stone from Loki and killing both him and Heimdall, Thanos uses the Power Stone to destroy the ship, leaving Thor to drift in space until he's found by the Guardians of the Galaxy.
The loss of the Asgardians is terrible, but for many fans, the only one that mattered is Tessa Thompson's Valkyrie. The bisexual Scrapper turned Revenger was one of the highlights of Ragnarok, and Thompson has been outspoken about the character's future in the Marvel Cinematic Universe. Although she said she would appear in Infinity War, she was nowhere to be found, and Thor doesn't mention her by name. What he does say, however, is that Thanos wiped out "half" of his people; the rest would get the opportunity to live on. It seems likely that Valkyrie is among those survivors.
When he touches down on a planet and razes it, Thanos appears to let people choose if they wish to live or die, at least to some extent. Gamora's flashback to when Thanos came to her home planet Zen-Whoberi confirms as much, and once everyone is equally distributed upon the two sides, his forces proceed with the culling. That logic, twisted as it is, likely came into play when he and the Black Order found the Asgardians; Thor probably had Valkyrie and Korg go with other Asgardians so the innocents had protectors wherever they went -- possibly to Norway, by way of Heimdall -- and then everything proceeded to pop off as we see it in the start of Infinity War.
Complicating matters is that, by the end of the film, Thanos has all six Stones in the Infinity Gauntlet and snaps his fingers, wiping out half of sentient life in the universe. It's unclear if his will is strong enough for him to keep his word and not make an entire planet or race extinct, because it looks as though he never goes back on his word. After all, he told Gamora about his journey back to her home world years later, where he found it thriving. If he's really in control of the Gauntlet as he says, then Valkyrie and the remaining Asgardians are likely safe.
What remains to be seen is how Thompson's character will factor into Avengers 4. Thor is one of the few heroes who remained untouched by Thanos' Gauntlet, and should Valkyrie be alive, he may ask for her help in setting the universe right again. Whatever happens, this isn't the end of Valkyrie, and she'll certainly be back for more adventures once Thanos has been defeated.
Directed by Joe and Anthony Russo, Avengers: Infinity War stars Robert Downey Jr., Chris Evans, Chris Hemsworth, Mark Ruffalo, Jeremy Renner, Scarlett Johansson, Paul Bettany, Anthony Mackie, Paul Rudd, Elizabeth Olsen, Tom Holland, Benedict Cumberbatch, Chadwick Boseman, Chris Pratt, Zoe Saldana, Dave Bautista, Bradley Cooper, Vin Diesel, Tom Hiddleston and Josh Brolin. In theaters now.