The one line from Avengers: Endgame that could hint at a future MCU storyline

***SPOILERS FOR AVENGERS: ENDGAME, OBVIOUSLY***

One of the most memorable lines uttered by Captain America in Avengers: Endgame could possibly hint at the future of the Marvel Cinema Universe. Well, maybe. Let us explain. ***ONE LAST SPOILER WARNING*** During the scene in Endgame where Cap, Iron Man and Ant-Man travel back to the battle of New York, there is a moment where Steve Rogers takes Loki's sceptre from the SHIELD agents who have apprehended it. They don't want to give it up because - as anyone who has seen The Winter Soldier knows - they are secretly agents of the nefarious Hydra. When it looks like they won't comply, Cap whispers "Hail Hydra" into their leader's ear, and they hand it over.

THE ELEVATOR SCENE HOLY FUCK I COULDNT BREATHE I MISS WINTER SOLDIER AND STEVE WHISPERING HAIL HYDRA REMEMBER WHEN THEY TRIED TO MAKE HIM HYDRA

— laura//endgame spoilers (@mycatwascool) April 24, 2019

It's a fun moment playing on the lore of the MCU - but for comic reading fans it is also a nod to an infamous moment in recent Marvel Comics history. The first issue of the 2016 series Captain America: Steve Rogers ended with the shocking cliffhanger of Cap exclaiming "Hail Hydra!" - revealing that history had been changed to make him a Hydra agent all along. https://twitter.com/ShacksMechac/status/1121424805658537984 The panel caused controversy amongst Marvel fans, and quickly became a meme - so Chris Evans saying it in the film had extra resonance. But could it actually point to a possible future storyline for the movies? The "Hail Hydra" moment kicked off the 'Secret Empire' mega-crossover in the comics, where it was revealed that the Cosmic Cube - aka the Tesseract in the movies - had been used to rewrite history and make Cap a Hydra sleeper agent, and saw the other heroes band together to stop him taking over the USA. Avengers: Endgame ends with Steve Rogers going back through time to return the Infinity Stones, and then choosing to remain in the past with Peggy Carter. He then reappears to Sam Wilson (aka The Falcon)  as an old man, to pass on the mantel of Captian America to him. Secret Empire also includes both an Infinity Stone affecting Cap's place in the timeline, and took place at a time when Sam Wilson was Captain America - letting Steve Rogers/Chris Evans be the villain. All this would seem to be the perfect set up for a Secret Empire adaptation if Kevin Feige and co wanted to go that way. Are we reading to much into this? Chris Evans has supposedly played Cap for the last time - but Disney could always drive a dump truck full of money up to his house to make it happen, we suppose. https://twitter.com/ChrisEvans/status/1047896966410190849