"to the end of the line" is a TikTok video posted by capwithoutacountry on 12 January 2022; the video is the 14th video in Fuchs's "Marvel What Ifs..." series.
It was Cap's fifth video on the platform to reach one million views, accomplishing the milestone in 109 hours on the evening of January 16th.
The video later reached two million views within 393 hours, on the morning of January 29th.
Transcript[]
"If I were to substitute James Buchanan Barnes for Tony Stark in that final confrontation against Thanos in Avengers: Endgame, after destroying the Quantum Tunnel, recovering the Nano-Gauntlet, and disabling Carol Danvers with the Power Stone, Thanos would have been attacked by the Winter Soldier, who would have put up a brief but surprisingly effective fight against the Mad Titan before eventually being thrown off. Thanos would have declared: 'I am inevitable', and then snapped, only to discover the Stones missing, and then he would have found Bucky standing amid the destruction, the Stones attached to his cybernetic arm, which, having been designed by Shuri, would have been outfitted with the same Wakandan nanotechnology as T'Challa's Black Panther suit. And as the energy of six assembled Infinity Stones ripped through him, Bucky would have looked at Steve when he told Thanos: 'I can do this all day'. And that line, more than anything -- more than all the times he wielded the Shield that he never officially got to carry during his lifetime -- would have represented his symbolic, if only momentary, transformation into Captain America and Steve's successor. And then he would have snapped, and as he lay dying on the battlefield in the aftermath of that costly victory, Rogers would have made it to his side, and Bucky would have mouthed Steve's name but been unable to make the sound, and Steve would have told him: 'I'm here, Buck. I'm with you...' And as Bucky saw the survivors gathering, knowing that all of the horrors he'd lived through and all of the sins he'd been made to commit had, in the end, made it possible for him to trade his life for the lives of everyone in the entire universe, his mouth would have twitched into one last faint smile, and Steve would have known that Bucky was already gone before he finished the sentence: '...to the end of the line'."