The implosion of the Brooklyn Nets' Big 3 finally completed itself this week with Brooklyn trading Kyrie Irving and Kevin Durant within a span of five days. Ironically, as the two Nets stars walked out the door, the long-lost third wheel in James Harden made his return Saturday night.

Harden took the floor at Barclays Center for the first time since forcing his way out of Brooklyn at last year's deadline. A chorus of boos rained down during his pregame introduction, as well as the first few times he touched the ball. The Sixers came from behind to beat the Nets 101-98 in a last-second thriller, but much of Harden's postgame questions surrounded Brooklyn's failed big three.

A year before forcing a trade from Brooklyn, Harden did the same in Houston. His method in doing so the second time around was eerily similar: he became detached from the team, hanging back on his own to party during a Nets West Coast trip while showing little interest when on the court. The guard's last game with Brooklyn was a four-point, six-turnover performance in which he showed alarmingly low effort:

At the time, Brooklyn's season was in ruins with Kevin Durant sidelined by an MCL sprain and Kyrie Irving missing over half the team's games while unvaccinated. Sources indicated the latter was a source of frustration for Harden, and the Sixers guard was asked Saturday if Irving's unavailability was the primary reason he left:

That's not something I’m gonna answer, but the reason I made that decision to get out of my comfort zone which was to leave Houston and do everything that I did to get out of there was to come here and play with KD and Kyrie,” he said via Alex Schiffer of The Athletic. “With that being said, that didn’t happen as much as I would have liked to or how much the organization would have wanted to. It’s just something I knew wasn’t gonna change.”

Whether Harden will explicitly say so or not, multiple sources chronicled his frustrations with Irving amid the guard's vaccination saga. The Athletic's Joe Vardon detailed what sources told him about Harden's reaction when Irving lit some sage in the locker room before a Jan. 17 game in Cleveland:

“In their locker room before the game, Kyrie Irving lit ablaze some sage — a Native American ritual Irving has embraced to cleanse negative energy,” Vardon said. “Irving doesn't do this before every game, but he apparently still feels haunted by parts of his past on the Cavs. So he lit his torch.”

“Harden, according to sources who were in the room when it happened, was seated in front of his locker, watching Irving, and looked at Kyrie like he had three heads.”

There was also a rift between Harden and Durant dating back to training camp. According to ESPN's Kevin Arnovitz, Durant was “astonished” by his teammate's poor physical condition heading into the season:

“Sources say that much of the discontent between Harden and the Nets started in September when he arrived into training camp out of shape,” Arnovitz said. “With Irving’s status already in flux due to his unwillingness to get vaccinated, Durant was astonished in the opening weeks of the season at Harden’s lack of explosiveness and sluggish play, something he attributed in large part to Harden’s being out of shape.

“Harden, sources say, found Durant’s slant grating and self-righteous. The two never resolved the conflict, and there was little that teammates, coach Steve Nash or Marks could do to mediate it.”

While he eventually asked Nets management for a trade to Philadelphia, Harden had previously hoped to avoid the backlash of asking out of his second franchise in two years. He was asked Saturday whether Brooklyn could have done anything to keep him:

“Yeah, there was, like, a lot of things. But it was just a lot of dysfunction. Clearly,” he replied. “But it was a lot of internal things that I’m not going to ever just say, put in the media or anything. And that was one of the reasons why I chose to make my decision. But now, fast forward to date, I don’t look like the crazy one.”

“I don’t look like the guy or the quitter or whatever the media want to call me. I knew what was going on and I just decided… I’m not built for this. I don’t want to deal with that. I want to play basketball and have fun and enjoy doing it. And fast forward to today, they’ve got a whole new roster.”

It is up for speculation what Harden is referring to when he says, “a lot of things.” Maybe that entailed getting rid of Irving, although that would not have gone over well with Durant. Maybe a change in management, maybe a mediation of the group's issues. At least for now, Nets fans are left wondering. What is abundantly clear: Brooklyn and the trio itself drastically underestimated the personalities at play when they formed the big three.

As you sift through the rubble of the failed era, the Nets are left with one playoff win and a lifelong supply of “what ifs.” And Harden offered a brief summation of his time in Brooklyn before walking out the door Saturday:

“Frustrating,” he said of the failed partnership with Irving and Durant. “There’s a lot of what-ifs. I think we only played less than 20 games together so it was a little bit frustrating, but it is what it is. Hopefully, everybody’s in a good place now and we can move on.”