The final seconds were a surrender, the Nets accepting their fate passively, letting the Bulls dribble out the clock, letting them get a head start on celebrating this 99-93 victory. The remnants of 17,732 at Barclays Center weren’t sure what to do. Mostly, they stared — at the floor, at the scoreboard, at the ceiling.

And then they were gone, the way this Nets season was gone, the way the promise of this first year in Brooklyn was gone. And make no mistake, when they left, when they disappeared into the subway or walked off toward the nearby parking garages, they took something else with them: the Brooklyn Nets’ innocence.

Starting this morning, first thing, the honeymoon ends on Brooklyn’s unconditional love affair with its basketball team. It was a nice run, 89 games in all, 52 of them victories. But that’s over. Starting this morning, starting right now, this is just another New York City team assuming the same burdens and blessings — and boo-birds — as the ones that play in Manhattan, or Queens, or The Bronx.

And frankly?

They need to be better than this. They need to be a lot better than the woeful effort that shoved them into a 17-point halftime hole, that made their fractured comeback attempts later on fruitless. They need max-out players who are the equal of their max-out contracts when a season teeters on the brink, when a series sits there for the taking.

“There’s no magic to it,” interim coach P.J. Carlesimo said, his voice fully landscaped by a hard night and a long season. “When you’re the 4 seed you’re supposed to beat the 5 seed.”

Carlesimo bore the look of a man who knew another open secret: The man who coaches this team going forward has to be better than what we saw last night, when it wasn’t just that Tom Thibodeau was playing chess and Carlesimo checkers; Thibodeau was playing backgammon and P.J. Candyland.