The first Loki trailer reveals the trickster taking on new roles as he travels through time and space, including becoming the notorious plane hijacker D.B. Cooper. After stealing the Tesseract and throwing himself into the void in Avengers: Endgame, Loki's fate has been a mystery until now. In the trailer, he is a prisoner of the Time Variance Authority, an organization that monitors all the different realities that exist in the multiverse. However, it seems Loki will be going to work for them, as the rest of the trailer showed Loki visiting different times, other worlds, and even traveling back in time to MCU movies. Among his adventures, a few clips that take place on a commercial plane clearly indicate that Loki is D.B. Cooper himself in the MCU.
The clips show Loki sitting on an empty plane wearing dark sunglasses and his usual victorious smirk. A flight attendant hands him a bag, and Loki says, "Brother, Heimdall, you'd better be ready," before jumping from the plane. The Bifrost activates and takes him away in midair, leaving only a small trail of money floating in the wind. The events match up with the real plane hijacking perpetrated by D.B. Cooper, an unidentified criminal who mysteriously vanished and was never seen again. At least in this new post-Avengers: Endgame timeline, Loki is that mysterious criminal.
The real D.B. Cooper boarded a plane from Portland to Seattle in 1971, and while the plane was in the air, he told the flight attendant he had a bomb in his suitcase. She took his demands: four parachutes and $200,000 in twenty-dollar bills. The flight landed in Seattle, and Cooper let the other passengers go in exchange for the FBI giving him the parachutes and the money. He ordered the crew take off again for Mexico City. Mid-flight, he jumped from the plane with a parachute, taking the money with him. No one knows what happened to D.B. Cooper, who used that name only as an alias to board the flight, and most of the money has never turned up again. Loki has a habit of cheating death in the MCU, so D.B. Cooper's long-shot escape is a tailor-made story for him.
The guise of D.B. Cooper would be a natural choice for a trickster used to changing names and faces, and the Bifrost is a perfect in-universe explanation for the disappearance of Cooper and the majority of the money, but it's still unclear why Loki would be hijacking the plane. It may be a mission from Time Variance Authority, but Loki could also be committing the crime under his own authority. Given that he's using the Bifrost to escape, he must be doing it for a legitimate reason, or at least legitimate enough for Thor and Heimdall. Thor's involvement in this plan also potentially sets up Loki's return in Thor 4, since Loki will already be working in alliance with his brother for at least one mission, though probably a version of Thor from 1971.
Loki's adventure as D.B. Cooper is just the beginning of the hijinks through time that he is sure to be embroiled in. The trailer teased a number of possible missions and mysterious figures Loki will be running across throughout time and space. The Time Variance Authority also opens the door to Loki's involvement in multiple realities, so not all of his missions necessarily take place in the main timeline. Alternate realities may also lead to multiple Lokis at work across the multiverse and the introduction of Old Loki in the series. There are already several questions about the trickster god's situation yet to be revealed in Loki, but fans will only have to wait until May 2021 to start solving the mysteries.