Next week sees the release of Avengers: Infinity War, the latest, long-awaited ensemble blockbuster in the Marvel Cinematic Universe (MCU). And arguably the biggest Marvel movie yet. Since kicking off with 2008's Iron Man, the MCU has expanded to almost unfathomable levels over dozens of films. The latest will see pretty much all of its heroes join forces on screen. An unprecedented cast We've certainly seen previous films bringing together combinations of separate heroes - such as the past two Avengers films and Captain America: Civil War. But Infinity War takes this to new extremes. It was reported earlier in the year that there will be at least 76 superhero characters from the Marvel universe popping up in Infinity War. Everyone from Iron Man to Ant-Man, Black Panther to Paul Bettany's 'Vision' are expected to make an appearance, and the promise of new combinations of characters teaming up to take on their foes in fresh ways is getting fans excited. Add into that the prospect of hidden connections, in-jokes and callbacks to previous films as various heroes cross paths and rub shoulders, and there'll be enough fan service to get even casuals excited. The Infinity Stones The Marvel 'franchises' within the MCU mostly have their own story-lines, but are all linked by a sub-plot involving the Infinity Stones; magical objects with the power to rewrite space, time, and reality itself. Josh Brolin's Thanos is on the hunt for the Infinity Stones (Photo: Disney/Marvel) Thanos (Josh Brolin) has been trying to collect them all for years, squirreling away in the narrative background, helping villains like Loki (Tom Hiddleston) in The Avengers, and Ronan The Accuser (Lee Pace) in Guardians of the Galaxy do his dirty work. At this point, most of the Stones are in the hands of the Avengers, but Thanos is increasing in strength and coming for the team of heroes, hoping to combine the Stones' power together with the 'Infinity Gauntlet' to become the most powerful being in the universe. Naturally, they have to stop him. Infinity Stones: What are they, where are they and who has them? End of an era It certainly feels like a film that will bring the curtain down on the current 'phase' of Marvel's films. While Phase 3 is technically coming to a close with an as-yet-untitled fourth Avengers film pencilled in for a 2019 release (that was originally announced as Avengers: Infinity War – Part 2), this film could serve as an huge change of direction for the series. Fans are excited to see the Guardians of the Galaxy rub shoulders with The Avengers (Photo: Disney/Marvel) At the very least, it will set into motion some pretty important events, and an epic battle that may not conclude until next year's Avengers entry. Two worlds collide Something that's been getting fans very excited, is the coming together of one band of heroes with another. When the first Guardians of the Galaxy film was released in 2014, fans were desperate to see the ragtag band led by Chris Pratt's Star Lord make their way into The Avengers' world, and in Infinity War, that is what they'll finally get to see. Home truths Fans in Scotland have a little something extra to be excited about: some Infinity Wars scenes were filmed in Edinburgh. Waverley Station was transformed for filming of the movie, and Edinburgh is expected to provide the backdrop to a dramatic attack by Black Order assassins on Scarlet Witch and Vision only for Captain America, Black Widow and Falcon to ride to the rescue. All of the above, plus the expected spectacle of Marvel's big-screen offerings, combine to make Infinity War one of the most anticipated comic-book films yet. Avengers: Infinity War opens in UK cinemas on Thursday, April 26 • Have your say on the latest TV and film with Screen Babble, our discussion group on Facebook This article originally appeared on our sister site, iNews.