The Marvel Cinematic Universe kicked off with an Iron Man origin story and promises of an epic team-up to come, but how will it all end?
Nobody knows the answer to that question, but one thing is clear: the MCU is on the verge of sweeping changes and is likely to be a radically different place two years from now, after 2019's untitled Avengers sequel has hit.
With the future of Marvel's old guard of Captain America, Iron Man, Thor, Black Widow, Hawkeye and Hulk uncertain, there were rumours the shared cinematic universe could reach its endgame with Avengers: Infinity War, back when the movie was a two-parter, but that doesn't appear to be the case.
Films including Spider-Man: Homecoming's sequel and Guardians of the Galaxy 3 are set to land in the ensuing years and the powers that be have confirmed that the MCU will endure in some shape or form post-Avengers 4.
So what could potentially stop this superheroic juggernaut? Will Marvel Studios bring it to some kind of organic conclusion many years from now? Or will external factors render the shared universe untenable at some point in the future?