NCIS - Mark Harmon, Gena Rowlands NCIS - Mark Harmon, Gena Rowlands

With appearances by Tony DiNozzo's father and Jethro Gibbs' former mother-in-law among others, this season's NCIS has been about the back stories and personal lives of NCIS team members.

"We've all had those opportunities on the show to dig more deeply into the characters and I think it's deserving," star Mark Harmon (Gibbs) said at the Paley Center for Media event about the series Monday night. "I think the fans deserve it."

Watch full episodes of NCIS

On Tuesday's episode (at 8/7c on CBS) the attention will turn to Gibbs when former mother-in-law Joann, played by Gena Rowlands, becomes involved in the team's latest case.

"What has been a recurring theme, at least this season, has been the focus on family and back story," said Rocky Carroll (Leon Vance). "That's been a central theme and I think it's going to continue. You're going to see more people out of the private lives of these characters."

The episode also marks the return of legal eagle and Gibbs' latest possible love interest, Allison Hart (Rena Sofer). But despite their on-screen chemistry, as well as her scheduled return for several episodes in May, Harmon said fans shouldn't necessarily anticipate a love connection. "I guarantee it's not going where people think its going," Harmon said. "I don't think [Sofer] knows where it's going any more than I do."

NCIS' 150th episode is a DiNozzo family reunion

Things also don't look good for Ziva David (Cote de Pablo) and Tony DiNozzo's (Michael Weatherly) immediate romantic future. However, cast members believe Ziva may have her hands full with family issues, namely her father. "I think it's going to have to come back because we left it unresolved. Basically, Ziva went against the will of her father, she went against the will of the Israeli Mossad," Carroll said. "Vance and Ziva's dad have a history and a relationship and it's under a lot of stress right now, so I'm looking forward to seeing how that gets resolved."

Gibbs and Ziva may be preoccupied with familial problems but one member of the NCIS team will find more luck in the love department. "Jimmy Palmer is going to have a little bit of a love interest," said Brian Dietzen, who plays Palmer. "His last love affair ended with Gibbs shooting her several times ... So far it's going well and the big spoiler alert is that she hasn't been killed yet. It shows us that Palmer is getting his confidence back a little bit in his love life."

Besides digging deeper into the NCIS team's love lives and family ties, Sean Murray, who plays Timothy McGee, explains the remaining episodes of Season 7 will also welcome back familiar faces. He was tight-lipped on names but did say the characters are "people you've seen within the last two years."

Carroll said the focus on team members' lives outside of the NCIS offices will add up in the end: "Everything is going to be building towards a pretty amazing finale."