TVLine has learned exclusively that FBI will host a Rookie Blue reunion when Charlotte Sullivan — who for six seasons played Gail Peck to Missy Peregrym’s Andrea “Andy” McNally on the Global/ABC procedural — guest-stars in multiple Season 6 episodes of the well-watched CBS crime drama.

Set in Toronto and airing June 2010 through July 2015, Rookie Blue followed a close-knit group of young cops trying to prove themselves. At the core of the group was Peregrym’s Andy, who — along with her friends Gail Peck, Dov Epstein, Traci Nash and Chris Diaz (and Andy’s on-again/off-again love interest love Sam Swarek) — experienced the trials, triumphs and tribulations of police work, as well as its effect on their personal lives.

Sullivan first FBI appearance comes in the next new episode, airing Tuesday, March 12 at 8/7c, where Peregrym’s Maggie Bell reunites with Jessica Blake, a former colleague and mom, kickstarting an arc in which Maggie herself mulls the idea of motherhood.

“Maggie is great friends with Jessica and her daughter,” Peregrym previewed for TVLine. “They’ve known each other since Quantico, but their paths cross professionally as their tasks intersect.”

Speaking to the Rookie Blue reunion at hand, Peregrym said, “I am thrilled that Charlotte joined our team to play Jessica. As usual, her talent and heart on- and off-screen have added to our show. After years apart from filming Rookie Blue together, it felt like seconds when we got back together. I definitely called her ‘Gail’ accidentally!”