Leroy Jethro Gibbs (Mark Harmon) will reunite with someone from his past in NCIS season 18 episode 14. This person played a significant part in the life of the special agent, but some unexpected events caused them to be separated. Now, his return is seemingly tied to the team's latest mission.

Phineas (Jack Fisher) is coming back in NCIS season 18 episode 14. The young boy is Gibbs' former neighbor, and they eventually developed a close relationship. He served as a mentor to the kid, though his mother, Sahar (Louise Barnes), turned out to be an adversary on Ziva David's (Cote de Pablo) side.

Now, Phineas shows up again and his return makes a huge impact on Gibbs. He has been dealing with a lot of things as of late, especially when Jack Sloane (Maria Bello) left. Also, he was suspended from his post due to his actions while on a mission out in the field.

As for how Phineas is coming back in NCIS season 18 episode 14, it has something to do with the latest case. According to the synopsis, the team will be tracking down a stolen laptop to the uncle of the boy. Right now, it remains to be seen how the kid's presence will play out in the story.

But, as seen in some of the preview photos, Phineas can be seen having dinner with Gibbs. The latter seems to be talking about something while the boy looks at him. They haven't seen each other for quite a long time, so there might be a lot of catching up to do.

As for what else is coming in NCIS season 18 episode 14, Gibbs is still suspended but he might be rejoining the team soon. Over the past few episodes, he spent most of his time at home, though he was previously called out in court to testify against a financial advisor.

In the promo of next week's episode, Timothy McGee (Sean Murphy) mentioned Gibbs potentially coming back to the office. The clip didn't show the latter in the department, but it looks like he is working with them despite his suspension -- possibly because of Phineas.

Meanwhile, this is going to be the second episode without Harmon's real-life wife, Pam Dawber, as the investigative journalist, Marcie Warren. The good news is that the character is coming back in the last two episodes and she'll remain to be part of Gibbs' storyline.

NCIS season 18 episode 14 is titled "Unseen Improvements" and it will air on Tuesday, May 11, on CBS.