‘Alert: Missing Persons Unit’: How Does Nikki Know Irish Mob Boss? Watch Sneak Peek (VIDEO)

The past comes back to haunt Nikki (Dania Ramirez) on Alert: Missing Persons Unit in Season 2. As TV Insider’s exclusive sneak peek of the March 12 episode reveals, it’s a messy (and mysterious) one.

Ian Tracey guest stars as Charlie McGannon, an old friend of Nikki’s—and current Irish mob boss—who asks her for an impossible favor. “Owen Maloy’s my problem,” he says in our clip. “I’ll handle him. Got it?” Of course, that’s not going to work for Nikki. She even reminds him, “We’ve known each a lot of years. I don’t remember—ever—a moment where I worked for you.” Charlie suggests she think of it as a favor for an old friend. “I don’t recall us being friends, either,” Nikki says.

“Don’t kid yourself, Nikki, I was there, remember? Treated you like a little sister when your marriage was falling apart. You wanted to climb the ranks real fast and make captain, and hey,” Charlie points out, looking around her office. So what exactly is their history? “You fed me intel, pointed me towards arrests,” Nikki acknowledges, “but this is different. You never asked me to look the other way back then.” Watch the full video clip above to see more of Nikki and Charlie’s dynamic. Who will fold?

“What really excites me about the introduction of Charlie is we get to know more of Nikki’s backstory and how she got to where she is, and her relationship with Charlie, as we introduce it in Episode 2, is a very complicated one,” showrunner Carla Kettner tells us.

This next episode, “Benjamin Franklin,” in addition to the introduction of Charlie, will see the MPU search for a Benjamin Franklin aficionado after he suspiciously disappears during one of his city tours. Plus, Jason (Scott Caan) and Mike (Ryan Broussard) try to bond as new partners (one of our favorite relationships on the show), and Kemi (Adeola Role) tries to manage the over-eager working style of the MPU’s new forensic scientist, Helen (recurring guest star Diana Bang).

Alert: Missing Persons Unit, Tuesdays, 9/8c, Fox