Melissa O'Neil Nathan Fillion

The Rookie Casts Nathan Fillion's Love Interest With Dark Matter Star

Dark Matter‘s Melissa O’Neil has copped a key role on ABC’s The Rookie, opposite Castle alum Nathan Fillion.

O’Neil has been cast in the coveted role of Lucy, an LAPD rookie who is intelligent, confident, tough and compassionate. She hails from a family of law-breakers, and is the first member of her brood to choose an honest, respectable path. (A previous version of this story listed the character’s last name as Benitez, though that will change.) During Season 1 of the new series, a budding romance develops between her and Fillion’s title character, John Nolan.

Earlier this week, Afton Williamson (The Night Of, Banshee) and Eric Winter (Rosewood, Secrets & Lies) joined The Rookie as training officers Talia Bishop and Tim Bradford.

O’Neil’s casting was first reported by our sister site Deadline. Her previous TV credits also include Lost Generation, Rogue, This Life and Canadian Idol (where she was the Season 3 winner).

The Rookiewhich nabbed a straight-to-series order from the network back in October — reunites Fillion with onetime Castle showrunner/EP Alexi Hawley and finds the TV fave playing the oldest rookie in the LAPD. Surrounded by noobs 20 years his junior, Nolan must navigate the dangerous, humorous and unpredictable world of a “young” cop, determined to make his second shot at life count.

Fillion will serve as an EP alongside Hawley (who will be Rookie‘s showrunner).