Credit: ABC Family Photo: Pretty Little Liars Season 2, Episode 2: Melissa Returns

So many classic Pretty Little Liars characters are coming back to Rosewood in these final episodes of Season 2. Melissa Hastings (Torrey DeVitto), who took a pregnant pause by going to Philadelphia, is making one of the most highly anticipated returns.

In this sneak peek from Season 2, Episode 21: “Breaking the Code,” Melissa is back in Rosewood, talking to Spencer (Troian Bellisario) about the news that Jason (Drew Van Acker) is their half-brother. Melissa seems just as surprised as Spencer was, if slightly less emotional.

But why does Melissa tell Spencer, “I’d rather not be here when Mom and Dad get home”? Is it merely because Melissa isn’t ready to face them now that she knows the truth about Jason? Or does she not want them to know she’s in Rosewood at all?

After Melissa’s fiance (and the father of her unborn child) Ian (Ryan Merriman) ostensibly committed suicide (although the Little Liars know that someone, likely “A,” murdered him), we learned that Melissa was having heart problems and went to live in Philadelphia.

In Season 2, Episode 16: “Let the Water Hold Me Down,” we also found out that Melissa lived just a few blocks away from the Philadelphia Home for the Blind, where Jenna (Tammin Sursok) was recovering and living after the accident. Just across the street is the newsstand where “A,” or one of “A”’s operatives, bought disposable cell phones.

Theory! Wouldn’t it be interesting if Melissa and Jenna, who are both proven Alison (Sasha Pieterse)-haters, worked together to kill Alison?

All of this mystery surrounding Melissa’s leave of absence from Rosewood, and her reasons for suddenly showing up just when the Little Liars are closer than ever to tracking Alison’s final footsteps before her murder, makes Spencer's sis look mighty suspicious.

Catch an all-new Pretty Little Liars on Monday, February 20 at 8pm ET/PT on ABC Family.

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