'NCIS' Season 15 Episode 22 Spoilers: Abby's Final Bow Will Be An Emotional Farewell; Reeves' Life Could Be In Danger Too

Abby Sciuto is about to make her final appearance in CBS' longest-running show NCIS this week, and it will definitely be a tough episode for all NCIS fans. Pauley Perrette warned fans that Abby's final episode would be packed with different emotions as the life of at least one agent is in danger while the rest of Team Gibbs will hunt for a hitman who targeted one of their own.

In a teaser trailer for this week's episode of NCIS, Abby (Perrette) is featured lying on a hospital bed while a ventilator is hooked on her. Agent Gibbs (Mark Harmon) is also seen standing at Abby's bedside. Towards the end of the sneak peek, Gibbs can be heard apologizing to unconscious Abby, saying that he should have done more to protect her. NCIS fans can understand why Gibbs is grieving over what happened to Abby.

Ms. Scuito has been considered a sister to all and a daughter to Gibbs. He cares a lot about her, and Gibbs saved Abby's life on many occasions. He also promised Abby that he would never let anyone hurt her.

So how did Abby get into this critical state? In the previous episode, Abby and Clayton Reeves (Duane Henry) were confronted by a mugger after their fancy dinner. The mugger fired his gun, but it wasn't revealed who got shot. Before the scene fades to black, Reeves pushed Abby away, so it's possible that it was Reeves who got shot.

The only thing that is certain at the moment is Abby got severely injured based on the Episode 22 trailer. It is also unclear what happened to Reeves after the shooting. He could have been injured, too, or possibly worse as he is noticeably missing in the latest teaser.

Speculations that Reeves could be hurt are rife because in the sneak peek. Agent McGee (Sean Murray) tells Director Leon Vance (Rocky Carroll) that things are "not so good" while standing outside a hospital room. It is unclear if they are talking about Abby or Reeves or both. Moreover, furious Nick Torres (Wilmer Valderrama) is also seen standing next to a body bag. Nick is asking someone how Abby and Reeve's lives were placed in danger.

Meanwhile, there are only two possible ways on how Perrette will exit the show—her character could either be killed or written off. If Abby will be written off, there are several ways on how it will be done. One of which is that Abby survives the tragic event but will eventually decide to leave NCIS for her safety.

In the upcoming episode, Abby could be the target of a hitman, who could also be the same man who attacked her and Reeves in the previous episode. Although Perrette refused to offer details about Episode 22, she hinted that there would be a character from Abby's past who will appear in her last episode and that person will play a crucial role in the plot.

"I actually can't say. Not because I'm not allowed to, but because there are so many different feelings. It's a cornucopia of emotions. And there is a character from her past who comes back and becomes pivotal to the plotline. There are tears, there are laughs, there are more tears and there's a lot of love. It's packed," Perrette told TV Guide.

Perrette has been portraying NCIS forensic expert Abby Sciuto for 15 seasons (over 350 episodes). The upcoming episode, titled "Two Steps Back," will be her last. NCIS Season 15 Episode 22 will air on Tuesday at 8/9 p.m. ET/PT on CBS.