By Kirsten Howard

Uncertainty and doubt plague the central duo of Marvel’s next Disney+ series.

After Steve Rogers handed his shield to Sam Wilson at the end of Avengers: Endgame, it seemed that Falcon might go on to take up the Captain America mantle.

Anthony Mackie’s character was clearly unsure about wielding the iconic shield, and some MCU fans were surprised that Sebastian Stan’s Bucky Barnes wasn’t offered it.

Bucky had been Steve’s best friend since before World War II, and the pair had gone through some tumultuous and often violent times, especially in recent years.

After Steve brought Bucky back from the brink and set him on the path to healing, Bucky was now reliable enough to join the good guys, perhaps permanently.

Broken and brainwashed by HYDRA, Bucky had been working with the bad guys for decades as the Winter Soldier - unbeknownst to Steve.

Meanwhile, Sam and Steve had become close friends, and the former had joined the Avengers, fighting alongside Black Widow and Vision as Falcon.

Both men have been Captain America at different points in their Marvel Comics history.

In their upcoming Disney+ spinoff series, Falcon and Winter Soldier are trying to find their place in a post-Captain America world where the Avengers have pretty much disbanded.

The Falcon and the Winter Soldier will feature enemies old and new. Daniel Bruhl’s Captain America: Civil War villain Zemo will return, uniting Sam and Bucky whether they like it or not.

The duo still aren’t on the best of terms, and their love-hate relationship will be tested even further by the arrival of John Walker aka U.S. Agent.

Walker, played by Overlord star Wyatt Russell, will be touted by the U.S. government as their new, patriotic version of Captain America who will always follow the rules—unlike Steve.

Sam might well be reluctant to step into Captain America’s shoes, but he may be forced to make a crucial decision rather than see Steve’s legacy be tarnished by Walker.

The latest trailer for The Falcon and the Winter Soldier sees both Sam and Bucky take turns fighting with Captain America’s shield.

But who will rise to the challenge of being a true leader in Phase 4 of the Marvel Cinematic Universe?