ravenswood brett dier elizabeth whitson 'Ravenswood' casting: Brett Dier and Elizabeth Whitson are twins Abel and OliviaOn the heels of announcing that Tyler Blackburn is joining “Pretty Little Liars” spin-off “Ravenswood,” ABC Family has revealed two more additions to the cast.

Brett Dier and Elizabeth Whitson have been cast as Abel and Olivia, twin teens who live in Ravenswood and whom the fans will meeting during the PLL Halloween episode that introduces the spin-off.

Dier has previously been seen on “The L.A. Complex,” but Whitson is a relative unknown so far.

Abel is a “lone wolf with an old soul” and Olivia is a “once carefree and happy spirit” who recently experienced a hardship. Not much else is known about the main characters so far, except that the show also features Miranda, a fiercely independent foster kid.

The spin-off revolves around the titular town, which has suffered under a deadly curse for generations. “Ravenswood” will at least be partially introduced before Halloween — Troian Bellisario just revealed Spencer and Toby are paying the town a visit this summer on “Pretty Little Liars,” which returns June 11 on ABC Family.

Posted by:Andrea Reiher

TV critic by way of law school, Andrea Reiher enjoys everything from highbrow drama to clever comedy to the best reality TV has to offer. Her TV heroes include CJ Cregg, Spencer Hastings, Diane Lockhart, Juliet O'Hara and Buffy Summers. TV words to live by: "I'm a slayer, ask me how."