Troian Bellisario (Spencer), left, and Janel Parrish (Mona) in ABC Family's Pretty Little Liars
Ron Tom/ABC Family
08/27/2014 AT 04:00 PM EDT
One of the main cast members of Pretty Little Liars
, ABC Family's breakout murder mystery, was killed in Tuesday's summer finale episode.
, who was the first "A" on the series, about an anonymous adversary who sends threatening messages to a group of girlfriends, talks to PEOPLE about her surprise death and what it means to the future of the show.
What was your reaction to finding out the news that Mona Vanderwaal would die
[Creator] Marlene King had been planning it for a year! She did a good job hiding it. I learned right before the table read for the episode two months ago. It's really fine. At first, I was definitely nervous, but she told me not to worry. I'll still have a job. I'm still on the show. I will be flashback girl. Fans will really like it. They'll get a little more insight into Mona's backstory. She's always been mysterious.
The way Mona's house was found [after her death], it looks like she put up a fight.
She definitely put up a fight. You'll see more of that in coming episodes. She wouldn't go out without a crazy fight!
If Mona had survived, what do you think Mona was planning
To nail Alison's [who the girls suspect is the new A] ass!
What was your favorite Mona moment
I really enjoyed seeing her that first day in a hoodie as A! It was a powerful moment for Mona and the show.
Will we see Mona in the Christmas episode
Yes! She will be the ghost of Christmas past, present and future! And she'll look fantastic in her costumes.
How is her boyfriend Mike going to react to Mona's death
That was such a sweet relationship. He's going to be devastated.
What do you think about the fan reaction to Mona's death
I'm so happy they are sad! She was so loved. RIP Mona
has been trending on Twitter! It's so great people are talking about it.
So it's good to know Mona is not history
I'm not going anywhere! I'll just be here in a different way.
Season 5 of Pretty Little Liars
will return on ABC Family in early 2015.