The star of the upcoming new crime drama The Rookie spoke to ET's Leanne Aguilera on Tuesday at the ABC upfront event in New York City, where he recalled her role on the beloved (but sadly canceled) crime series Castle. In 2012, Markle appeared in a one-off, fairy tale-themed episode that saw the likes of Snow White and Red Riding Hood getting murdered.
As for the future royal family member? She played Sleeping Beauty. Fillion fills in the spoiler-filled details.
"I remember the entire episode and I remember she was one of our fairy-tale princesses," he told ET. "I forgot that she was the murderer and I am shocked! I am shocked!"
"What a wonderful surprise!" he joked. "How lovely for her! Congratulations."
Markle has popped up in a few surprising places in her acting career outside of her starring role on Suits and as a heartless fairy-tale princess murderer. She made a brief appearance as a FedEx delivery driver in Horrible Bosses, she was a suitcase model on Deal or No Deal, she played "hot girl" alongside Ashton Kutcher in the 2005 romantic comedy A Lot Like Love and appeared as the inquisitive FBI Agent Jessup in an episode of Fringe.
Fillion's new crime drama, The Rookie, airs this fall on ABC.
For a closer look at some of Markle's surprising celebrity connections, watch the video below.