Time travel is a well-worn topic in the funnybook world, and just about every form of medium. The desire to go back into your past and fix your mistakes is a strong one, and fodder for all sorts of interesting stories and head-breaking paradoxes. It's so well-ingrained in our consciousness, though, that even the least science-fictionally adept among us know the dangers of messing with history. You don't go back in time because you miss your mommy, because that's how you end up with The New 52 and turn Billy Batson into a dickhead. Most time travelers know to keep their meddling to a minimum.
Most time travelers aren't the Thunderbolts.
Ever since Fear Itself wrapped, these criminals-turned-slightly-less-criminal have been lost in the timestream, while half of them work on the problem and half of them get in trouble and need to be corralled. Now, they've landed in the aftermath of Onslaught, meeting the original incarnation of the Thunderbolts – back when they were led by Baron Zemo and masquerading as heroes. The roster has changed significantly since then, but two of them remain. Moonstone has already conspired with her past self to change her own future, but the Fixer, when confronted with his younger and "full of piss and vinegar" self being disgusted with what he's become, snapped and murdered his past self.
That's a big no-no.
The resulting rip in the space-time continuum kills the entire universe outside of their temporally-displaced headquarters, and Thunderbolts #174 consists entirely of the panicked ne'er-do-wells trying to do well enough to preserve existence. The solution is haphazard and crazy, and it requires a steep price to be paid by the modern-day Fixer, aka Norbert Ebersol, who mysteriously didn't vanish the instant he killed himself. In his decision to undergo a memory wipe and a quick de-aging (thank you, handy brilliance of Centurius) in order to take his own place in the past, thus condemning himself to live in an infinite loop, he simultaneously gives up on his struggle to "go straight" and completes that journey at the same time. It's a moving fate he accepts for himself, happy to be able to live as the self-absorbed pseudo-criminal again instead of the morally-conflicted sourpuss he'd become. It's a brave enough sacrifice that even the broken Karla Sofen has a moment of humanity in thanking him for it.
Jeff Parker's engagingly epic arc isn't quite over, as we don't know the fate of these chronologically challenged miscreants, and we'll be derailing for awhile into a publicity stunt – er, a modern-day diversion where Luke Cage is running The Dark Avengers. That's a concept that's run its course, but it has 'Avengers' in it, so milk it. Parker's more than earned the benefit of the doubt as far as taking eye-rolling concepts and making them good – like the Red Hulk, for instance, and our fingers are crossed that maybe he can take over Incredible Hulk soon and quickly erase Jason Aaron's absolute misfire take on a character who should be awesome right now to cash in on movie interest… but I digress. The art from Declan Shalvey is also sweeping in its destructive swath and tense with its claustrophobic sense, although it's still a bit hit and miss.
Hopefully, the actual Thunderbolts won't be lost for long, and the Dark Avengers stint will bring in some new eyes who will then be schooled in compelling moral ambiguity that doesn't need 'Dark' tacked onto it like this was 1993 or something. In the meantime, Thunderbolts #174 is a great send-off to the Fixer, a character who absolutely encapsulates that ambiguity and goes out chock full of it.