The Fast and Furious movie franchise is no stranger to ridiculous stunts, so bringing Han Lue back from the dead for Fast and Furious 9 isn't that far-fetched. Played by Sung Kang, the character was killed off in the third movie, The Fast and the Furious: Tokyo Drift, but proved to be so popular among fans that (thanks to some timeline shifting) he also returned in Fast & Furious 5 and Fast & Furious 6.
The circumstances of Han's death seemed pretty definitive at the time. During a high-stakes car chase his car was T-boned and flipped over onto its hood. Tokyo Drift's protagonist, Sean, ran over and very clearly saw an injured Han trapped in his seat - right before the car exploded in an enormous fireball. Fast & Furious 6's mid-credits scene, along with Fast & Furious 7, revealed that it was actually Deckard Shaw behind the wheel of the car that crashed into Han's. This was an act of revenge for Dominic Toretto's crew seriously injuring Deckard's brother, Owen Shaw, at the end of Fast & Furious 6.
A funeral was held for Han in Fast & Furious 7, after Dom supposedly collected his friend's remains from Tokyo. However, at the end of the trailer for F9 Han walks into the crew's headquarters - alive and well, with no obvious scars or debilitating injuries. The only person who seems to have prior knowledge of his survival is Letty (which is appropriate, given that she also once returned after being presumed dead in an explosion). So, how is Han alive? We have a couple of theories.
Han Managed To Escape the Explosion
Never underestimate the power of a simple retcon. While the original cut of Han's death in Tokyo Drift seemed to clearly show him being in the car when it blew up, it would be easy enough to create a flashback where we see Han wriggling free and then being blown clear of the explosion. From there, it could simply be explained that Han was injured just enough to take him out of the fight for a while, and/or he decided to fake his death in order to escape Deckard Shaw's wrath. This explanation would be effective, but very cheap, so hopefully F9 comes up with something a little better.
Hobbs & Shaw Technology Revived Han After the Explosion
The Fast and Furious franchise recently branched out into a spinoff movie, Hobbs & Shaw, in which the villain just happens to be a character who came back from being "killed" by Deckard Shaw. Brixton Lore was a former MI6 agent who joined a terrorist organization called Eteon. After Deckard put a bullet in his head, Eteon recovered his body and used highly advanced technology to give him cybernetic limbs and other enhancements, turning him into (in his own words) "black Superman." This opened up a whole new world of possibilities for the Fast and Furious franchise - including the possibility that Eteon (or someone with access to the same technology) might have brought Han back from the dead.
Though Fast and Furious fans have been demanding #JusticeForHan and should therefore presumably be happy about his return, it still needs to be handled well. Han's death carried a huge amount of emotional weight for Dom and the rest of the family, not to mention the fandom, and so his resurrection deserves just as much justice as his death.
