The Umbrella Academy's trip back to the '60s was a lot more emotionally fraught than expected, thanks to some budding romances. Vanya, Allison, Diego, and even the ghostly Ben all wound up falling hard for someone in the past, but it was Klaus' complex love story that was the most disappointing. Despite the frustration, though, there's a detail about Dave in the Umbrella Academy Season 2 finale that's pretty reassuring, and most viewers probably missed it.
Spoiler alert: This post contains spoilers from the Season 2 finale of The Umbrella Academy. Viewers first met Dave in Season 1 when Klaus traveled back in time to 1968. Dave served alongside Klaus in the Vietnam War, and before Klaus returned to the present, the two professed their love for another. Sadly, Klaus watched Dave die on the battlefield shortly before he returned to 2019, and preventing that death became his primary motivation in Season 2 when the whole Umbrella Academy found themselves stuck in 1963.
Klaus was able to track down a younger Dave in Dallas before he enlisted in the U.S. Army, but of course, it's not super easy to explain to someone that you're their true love from the future who knows exactly how they will die. Despite Klaus' best efforts to warn Dave against going to war, he wound up enlisting anyway.
In his final scene, Dave climbed onto the military bus after longingly looking in the distance, presumably for Klaus to try to stop him one last time. Dave's last glimpse searching for Klaus was certainly heartbreaking, but something else happened in that scene a lot of fans probably missed. The officer herding the new recruits onto the bus called Dave a Marine, confirming Dave actually did take Klaus' advice to heart to some extent. As pointed out by fans on Reddit, in the original timeline in which Dave died, he was in the Army, so enlisting for the Marines instead might actually change Dave's fate.
But of course, there's still a heartbreaking aspect of this change: Because Dave is in the Marines and not the Army now, Klaus will never meet him when he travels back to 1968. On the bright side, though, the change has the potential to save Dave's life. There's even the chance Dave could survive up to the year 2019 and still be around in the present timeline because of this, so there could even be another Klaus and Dave reunion in Season 3. The officer's line may have been easy to miss, but it really does have the potential to change everything for Dave.