Agents of S.H.I.E.L.D. has wrapped up its run after seven seasons and more than 130 episodes. The series finale recently aired on ABC, which gave Agent Coulsen and the gang their send-off. Even though the show has felt largely removed from the events of the Marvel Cinematic Universe, especially in recent years, the finale did feature one major connection to Avengers: Endgame.
Warning: massive spoilers ahead for the Agents of S.H.I.E.L.D. series finale. Read on at your own risk. Fitz had been missing for most of the show's final season but, about halfway through the finale, Iain De Caestecker's fan-favorite character finally showed up. As we come to learn, the timeline that Coulson, Daisy and the rest of the core group of characters had been exploring this season was actually a branch reality far removed from the core timeline we know from the MCU. All of the changes to the timeline created this branch reality.
The time travel rules, as laid out in the show, mirror the rules as explained in Avengers: Endgame. Time travel in the MCU has very specific rules that differ largely from other prominent examples in pop culture. Fitz, we discover, opted to stay behind and use the Quantum Realm to travel to the branch reality in order to take the group back to their universe and stop the Chronicoms. Fitz, in the episode, explains it thusly.
"You went back in time and then you branched off. But we can travel through something called the Quantum Realm. So we can go in between timelines."
A huge part of Ant-Man and the Wasp, the Quantum Realm allowed the Avengers to traverse time and undo Thanos' deadly snap in Avengers: Endgame. Introducing these same ideas in Agents of S.H.I.E.L.D. provides major connective tissue between the show and the movies of the MCU. But, as co-showrunner Jed Whedon explains, the idea was hatched before Endgame hit theaters.
"When we first started talking about it, it was before 'Endgame' had been released. We knew that there were certain things we could not do... It's one universe and we tried to be true to it... We didn't want to play the same game that they were going to play."
While early seasons of the show were heavily connected to Captain America: The Winter Soldier, with cameos from Samuel L. Jackson (Nick Fury) and Jaimie Alexander (Lady Sif) to help anchor it to the MCU, Agents of S.H.I.E.L.D. largely felt removed from what was going on in the movies. So bringing in the connection in the finale was undoubtedly significant. Now, Marvel Studios is looking to the future with a new wave of live-action shows being produced for Disney+, such as The Falcon and the Winter Soldier and WandaVision, that will be directly tied to the movies. This news comes to us via The Wrap.