Jennifer Garner Gushes Over 'Alias' Reunion With Victor Garber on 'The Last Thing He Told Me' (Exclusive)

Sydney and Jack Bristowe are together again!

Jennifer Garner is thrilled to be working with her TV dad once more! In an interview with ET's Nischelle Turner, the 50-year-old actress gushes over the opportunity to appear alongside Victor Garber on her upcoming series, The Last Thing He Told Me.

The pair starred as a father-daughter spy duo on Alias, and are reuniting on the Apple TV+ series. This time around, Garner is playing Hannah, a woman who works to discover her husband's (Nikolaj Coster-Waldau) secrets after he mysteriously goes missing, and turns to his old professor (Garber) for help amid that journey.

"Lucky for me, our showrunner, the brilliant Josh Singer, happens to be a major theater geek. Victor is a huge Broadway star first and foremost. So, Josh and I conspired," Garner tells ET of how Garber came to join the project.

"We talked about how could we get Victor in here? What role would be right for him?" she adds. "It just worked out perfectly that we were able to have Victor."

Having him on board was a no-brainer, as Garner considers Garber to be "very much part of my chosen family."

"He really thinks he's my dad. I mean, I speak to him every Sunday. I spoke to him yesterday. Every single Sunday of the world," she says. "I check in like you checked in with your parents. Half the time I take care of him, half the time he's taking care of me."

It wasn't always easy working with Garber, though, as Garner explains, "The only problem was I kept smiling at him. I kept, like, breaking character and just looking at him, because I'm just so proud of him."

Even so, for Garner, reuniting with Garber made her feel like no time had passed since their Alias days.

"It really reinforced for me the idea that we should work with the same people again and again and again, because you just start that much further down the field, because you already have just this comfort and trust built in," she says. "That was really exciting for me."

Also exciting for Garner was working with Reese Witherspoon on the show, as the Oscar winner's production company, Hello Sunshine, is behind the series, which is based on Laura Dave's book of the same name.

"It's so propulsive, the read, because the stakes could not be higher. They are turned on a dime again and again and again. And in the middle of it is this very tender love story between a woman and her stepdaughter, and kind of the idea of becoming a parent," she says. "So you mush all of that together, and forget it. I mean, I just don't know what... more you could ask out of a role."

Just as much as Garner enjoyed stepping into Hannah's shoes, Dave tells ET that she's not over the fact that so many A-listers are bringing her book to life.

"It's a dream come true," she says. "Very early on, Jen and I had this conversation about Hannah being the grown-up in the room. I truly believe that no one could go from being the grown-up in the room to the hero of this story, except for this woman."

The Last Thing He Told Me will premiere April 14 on Apple TV+. Tune in to Tuesday's episode of Entertainment Tonight for more of ET's interview with Garner.