Get your tissues ready! Pauley Perrette has filmed her final two episodes of NCIS. The 49-year-old actress, who played Abby Sciuto since the show began, announced season 15 would be her last in October 2017. Giving fans a behind-the-scenes look at her last day on-set, Pauley reveals Abby's goodbye will run over two episodes. "Abby's exit from #NCIS is in two parts. May 1 and May 8th," she tweets. "I worked really hard to give you my best. I really hope EVERYONE tunes in. Bless."

As one of three remaining original characters (only Mark Harmon [Gibbs] and David McCallum [Ducky] have appeared in every episode since the show's premiere in 2003), the loss of the quirky Abby is devastating fans. "Wow, the end of an era," one tweets. "I love Abby so much! She instantly because my favourite character right from ep 1." Another fan adds: "I can't believe that you are leaving NCIS! It will never be the same without you! Abby will be missed more than you know and you Pauley Perrette can never be replaced!"

Abby Sciuto has been a fan favourite since the start.

Pauley's abrupt departure, coupled with the fact she isn't appearing in scenes with co-star Mark Harmon in the current season, has fans speculating online there's something larger at play. "I heard something about Mark bringing his dog to work, [and it bit] one of the crew members," says Cyndie Harper on Twitter. "And she [Pauley] didn't feel that it was right that he was [still] bringing his dog [to the set]." Supporting the rumour, another fan explains: "Apparently, producers backed Mark up and brushed the dog attack under the rug. Shortly after, her scenes with Mark started diminishing then stopped completely. Then, she announced she was leaving after season 15."

The cast of NCIS has lost a few favourites over the years.