Fin and Rollins duck out of Benson's swearing-in as a new sergeant to investigate a strange kidnapping call involving two missing teens, Avery and Manny. Avery's parents claim that her former boyfriend assaulted her before the kidnapping, and their assertion holds water once Amaro discovers evidence that Manny runs with notorious gang BX9. SVU hauls him in for questioning, and Manny admits to seeing Avery the night before - but not to sexual assault or kidnapping. Turns out he's telling the truth - an alert sends Rollins to a rooftop where Avery, battered and emotional, stands at the very edge, rambling about Manny's death. Rollins assures her he's alive at the precinct, but that's not enough - Avery plunges toward the ground and lands, thankfully, on an inflatable platform prepped by the NYPD.
At the hospital, Avery admits to a grim scene from last night - gang members from BX9 raped her and forced Manny to watch. While Amaro and Fin drag in the accused rapists - each of whom boast about Avery enjoying the sex and insisting the acts were consensual - Benson informs her that Manny refused to give up the BX9 rapists (and thus remains an accessory to the crime). Avery adds to her story, wrecked by the thought that Manny would be angry with her. Despite the pain and suffering, Avery describes how she achieved involuntary orgasm during the rapes - something that she never experienced with Manny. She breaks down, certain that he must think she enjoyed the sex.
Meanwhile, Fin and Amaro zero in on a new angle with Manny - what if BX9 raped Avery as a form of retribution against Manny? They drill into Manny's brief history with the gang and discover he froze during a solo drug robbery, losing out on the loot. If this plays into the story, Avery doesn't care - she demands to speak with her boyfriend. Benson arranges for a meeting at Rikers, but even after Avery levels with Manny, he refuses to testify in support. With the case stalled, Avery's family takes her on a quick trip outside the city - interrupted almost immediately by BX9 members on motorcycles who surround the vehicle, smash the windows and assault the family.
Avery, understandably, declines to testify after she and her family recover from minor cuts and bruises, leaving SVU once again without a solid lead - until Amaro dusts off a file that connects BX9 to the death of Manny's brother. Amaro and Fin return to Manny with the new evidence, and Manny folds under their pressure, revealing his true hesitance to testify - the gang told him they were coming over "to party" and he knew that was code for rape. Despite this knowledge, he let it happen; he allowed Avery's sexual assault. He tapes his testimony with the understanding that protective custody will keep BX9 at bay, but before the tape makes it to a courtroom, Benson takes a call from Rikers - Manny was found murdered, with his tongue cut out.
With Manny dead, his testimony is inadmissible - unless SVU proves that BX9 had Manny killed to prevent him from testifying. This angle leads Fin and Rollins to the apartment of the BX9 leader, where they bait his girlfriend with stretched truth on his role in the sexual assault. SVU tapes the conversation that follows, and when Benson and Barba approach the leader with the recording, he threatens Benson - and she threatens him back, describing the NYPD as the tightest gang in New York. The leader backs off, and it's clear his lawyer wants to make a deal.
The case now in hand, Rollins visits Avery for a follow-up. She's still traumatized by the event, but channeling that pain into art. Although Manny failed to prevent the rape, he sacrificed himself for her, knowing all along BX9 would kill him. Yet more than anything, Avery regrets not telling Manny she loved him while she still had the chance.