Nathan Fillion and The Rookie cast introduce their squad of characters

Welcome to the force

When an unmoored, fortysomething small-town divorcé named John Nolan (Nathan Fillion) pursues his dream of becoming a cop, not everyone's on board. Ahead, the cast of ABC's The Rookie and executive producer Alexi Hawley introduce the characters.

John Nolan (Nathan Fillion)

Though the titular rookie is a bit old for his new job, Officer Nolan is no amateur when it comes to life experience. By the time he pursues his drastically different career, he's already built a family, seen his son off to college, and gone through a divorce. "John Nolan's strength is that he has lived for [40-plus] years," Hawley says. "He's a rookie police officer with an empathy 25-year-olds don't have." It's a change Fillion says he's noticing more and more: "This is a cultural shift we're seeing, where people are starting their lives over halfway through."

Lucy Chen (Melissa O'Neil)

The Dark Matter star plays one of Nolan's fellow rookies, a standout cop who gets paired with the toughest of the training officers, Tim Bradford (Eric Winter). Luckily, Lucy's a quick learner, and Tim's no villain. "It's not easy having an ensemble show of eight people and having them fleshed out," O'Neil notes. "They're all human beings with interesting stories, that make you want to root for them and make you want to see them succeed."

Jackson West (Titus Makin)

The youngest rookie arrives at the LAPD saddled with high expectations from everyone around him: As the son of a commanding officer, he comes with plenty of baggage. "He's coming in with a lot of eyes on him," Makin (The Path) explains. "Everyone's assuming I got there as a handout, as opposed to my actual knowledge and ability."

And as much as West is afraid to fail, a secret he's keeping about a key part of the job may just make his fears come true…

Angela Lopez (Alyssa Diaz)

Because she was raised, along with her four brothers, by a single mother, training officer Lopez has "a tomboy vibe," Diaz (Ray Donovan) says. She's got a competitive streak, and when the series begins, she's angling to become a detective — a goal her fellow TO Talia (Afton Williamson) is after as well — while also attempting to help rookie officer West overcome his issues. “She's trying to figure out, ‘How do I stay alive, how do I keep this rookie alive, and how do I work my way up?’” Diaz says.

Tim Bradford (Eric Winter)

Don't let that smile fool you: Training officer Tim Bradford couldn't care less if the rookies — or even his colleagues — like him. "He has a very hard exterior and comes at everyone hard with a form of judgment," Winter (Rosewood) says. “Think of him as a drill sergeant in the military.… He comes from a mentality of, ‘I'd rather break you and then teach you. If you're breakable, then you shouldn't be here.’”

That said, the toughness exists for a reason. "You'll get a glimpse of who the guy is behind all the bravado," Winter teases. "There is this very broken individual who is trying to put the pieces together in his personal life."

Talia Bishop (Afton Williamson)

Lopez's primary rival for the detective gig is an intuitive training officer who gives her job her all. Partnered with Officer Nolan, Bishop tries her best to make sure he's "a sponge." And in preparing for the series — a process that included speaking to real-life cops and going on ride-alongs — Williamson (Shades of Blue) says she grew to appreciate the gravity of the job, especially after police shootings of unarmed black men drew national headlines and launched a movement: "It's sad to have a couple [officers] mess it up for everybody, but doing this, I did have a bit more faith in our actual police, because I see how hard it is and how difficult it is."

Sergeant Wade Grey (Richard T. Jones)

Out of everyone in the squad, Grey is most uncomfortable with the idea of a fortysomething rookie — and with good reason, Jones (Santa Clarita Diet) says. "He's a hard-nosed, old-school type of cop, who cares deeply for his people. He's no-nonsense, so when Officer Nolan comes in, [Wade] just believes that he's too old to start looking at things in a new way," the actor explains. "He fears that that could be a bad element for his particular squad."

Still, don't expect Grey to simply be the villain of Nolan's story. "I've played a lot of tough guys, but Sergeant Grey has a really compassionate heart," Jones says. "Everything he does, he does for his people's safety and for their betterment."

Captain Zoe Andersen (Mercedes Mason)

If Grey's not on Nolan's side, at least Captain Andersen is — she's the one who brought him in, after all. "She understands that once you've lived your life, you're going to see problems differently," Mason (Fear the Walking Dead) explains. "The other cops don't always look outside the box."

As for Andersen herself? "She's determined, and she's worked very hard," Mason says, adding that she spoke to real female captains to research the role. "She's strong and relentless, and she's not going to let anyone push her over." Especially not those challenging her hires.

The Rookie premieres Tuesday, Oct. 16, at 10 p.m. ET on ABC.