and had an instant connection when they auditioned for — even though Hargitay thought she was auditioning with a different actor.

The two actors co-starred on the crime series for 12 years as beloved detective duo Olivia Benson and Elliot Stabler, and though Meloni left in 2011, they have in the years since.

When they first met for a screen test, however, Hargitay, 57, expected to see star John Slattery in Meloni's place.

"I walked in, she turns around and goes, 'Slattery!' I go, 'No, Meloni!'" Meloni, 59, tells PEOPLE in this week's cover story.

"From that moment forward… we walked into the screen test, me telling her a story, and we get up onstage in front of all the suits, and we're just so engaged. We said to the execs there, 'Just give us one second. I just need to finish this story. It's really funny.' From then on it was like, 'We got this,'" he continues.

Hargitay also felt the instant bond — "I walked in, saw him, and I went, 'That guy. That's the guy.' It went deep, very fast. We both knew that it was something big," she recalls. "I won't say that I fully understood it, but I knew that meeting him was important and life-changing.

My father, my husband, [ creator] Dick Wolf and Chris are the four pillar men in my life. And that happened early."

When Meloni abruptly left the show after contract negotiations fell apart, Hargitay continued playing Benson. In 2019, became the longest-running drama series in TV history. Still, Hargitay says she was "" by his departure.

"I was just so sad, because we started this thing and built it together, and we went through so many milestones and spent so much time together and understood so many things that nobody else could understand," she says.

"I had to do so many mental gymnastics and sort of do a reinvention in my own mind, which of course turned out to be a gift, as any sort of growth is. But I was scared; I was sad."

Meloni, however, saw things differently. "She was left in the familiarity of what we were. And I'm sure there were echoes, constant reminders, everywhere. But for me, it was about how things fell out—and the word I'll use is that it was inelegant," he says.

"At the end of the day, how it was handled was, 'Okay, see you later.

' So I went, 'That's fine. We're all big boys and girls here. See you later.' And I was off on new adventures and doing what I wanted to do. Telling the stories I wanted to tell," adds Meloni, who went on to appear in numerous TV series, including and , as well as several films, like and .

"I couldn't have been happier. But she and I," Meloni says, "we stayed connected."

That connection has never been more apparent than when the two began filming again for , a spinoff series premiering April 1 in which Meloni's Stabler is the central character.

"It was Pavlovian: Ring that bell, and you get right into Stabler and Benson," Meloni says.

"There was so much shorthand between us, which all goes back to the trust we have," Hargitay adds. "He's always made me feel like I could just jump off the ledge, the cliff, the bridge, and he would catch me, in so many ways, whether it was comedy or acting or friendship."

"It's simple," Meloni says. ".