I think everyone dying qualifies.
In an effort to woo Mistress Death, Thanos has already vanquished half the population of the entire universe using the power of the assembled Infinity Gauntlet. He’s achieved godhood, and now he wants love.
In #4, a band of surviving superheroes mounts a major offensive against Thanos while his captive half-brother, former Avenger Starfox, narrates from the sidelines. Mephisto, who’s basically Marvel’s version of the Devil, convinces Thanos to dampen his omniscience to give the heroes a sporting chance—in doing so, Thanos would display courage in battle and could thereby impress Mistress Death, Mephisto reasons.
So the heroes have a minuscule chance of victory against a supremely powerful villain, but they fight anyway. And they fall—and die—one by one, until Captain America is the last man standing against the mad god. Cap has his big hero moment staring down an opponent he has almost no chance of defeating.
It’s an absolutely classic Captain America scene that says a great deal about his character. While Thanos is pretending to be brave to impress someone, Cap is legitimately displaying supreme courage with no ally left to witness it as far as he knows.
And he dies. The good guys fail. And there are two issues left!
As a whole, The Infinity Gauntlet is cosmic-scale comic book storytelling at its finest. A universe in peril, life-and-death struggles, a twisted version of courtship—quite a bit going on here, all of it entertaining.
Writer: Jim Starlin
Artists: Ron Lim and George Perez
Cover: George Perez
Publisher: Marvel Comics
How to Read It: back issues; Marvel Unlimited; Comixology; included in The Infinity Gauntlet (TPB)
Appropriate For: ages 12 and up