"Original Sin" quickly establishes Karen Beasley (Mallory Bechtel) as the high school mean girl who bullies Imogen, Tabby, Faran, Noa, and Mouse for different reasons. Viewers also learn her identical twin, Kelly (also played by Bechtel), has a complicated relationship with her sister — one that isn't fully explained or developed before Karen is ultimately murdered by "A" at the end of episode two.
Fans of "Pretty Little Liars" will remember that when the original Liars think Ali is dead, it turns out to be the body of Ali's twin sister, Courtney DiLaurentis, and Ali is still alive, making "A" and Ali's backstory even more of a mystery.
The question of whether any of the original Liars will appear in "PLL: Original Sin" is still not answered, but the existence of twins in the spinoff mirrors this element of the original to an eerie degree. And because Kelly and Karen do switch places early on in "Original Sin," it begs the question of which twin actually died and which one is now choosing to help the Liars get out of trouble and solve the mystery of who "A" is.
