TV

‘Pretty Little Liars’ ready to spin (off)

ABC Family’s “Pretty Little Liars” has become a social media phenomenon, with its Season Four summer finale last August setting the record for the most tweeted series episode in TV history — 1.9 million — for the big reveal that Ezra is the infamous “A” terrorizing the Liars.

“PLL” will seek to break that record with its annual Halloween special airing Tuesday, Oct. 22 at 8 p.m. The episode features the Liars crashing the Ravenswood Founder’s Day Celebration to try to find their missing friend Ali before “A” can, and producers are promising more Tweetable O-M-G moments.

“It’s a game-changing episode which takes our four girls down a different path completely,” says “PLL” executive producer Oliver Goldstick. “A provocative piece of information is revealed in that Halloween episode. Put on knee pads because you might fall off the couch when you get to the end.”

“PLL” consistently ranked as a top 10 show on Twitter last summer with its with its more than 1.8 million Twitter followers who generated an average of 10,000 tweets per minute for the finale. And though a star from the show livetweets each episode’s east coast broadcast, the writing staff doesn’t use the fan feedback — which can sometimes be nasty.

KICKER KICKER: “Ravenswood” will star Nicole Gale Anderson (left) and “PLL” player Tyler Blackburn (right).Skip Bolen/ABC Family

“Of course if you’re planting surprises you certainly want reactions,” Goldstick says. “I can’t be enslaved to what is popular. We’re not taking a vote. This is not ‘The Voice.’”

Nielsen started measuring tweets for TV shows in October, but the relationship between Twitter activity and ratings remains murky — the record-breaking premiere of “The Walking Dead” drew 16.1 million viewers to 1.2M tweets.

In the case of “PLL,” there seems to be a correlation. The summer finale that set a Twitter record averaged 3.3 million total viewers and 2.1 million adults 18-34, a network telecast record in the key demographic.

The Halloween episode will also set up the series premiere of spinoff “Ravenswood” which follows at 9 p.m. and centers on the titular town where five strangers (including “PLL” star Tyler Blackburn) connected by a deadly curse must dig into the town’s supernatural goings-on before it’s too late. “Ravenswood” will move to 8 p.m. the following week where it will air until “PLL” returns in early January.

“Ravenswood” is already set to follow in “PLL’”s social media busting footsteps (the series was fittingly announced last March on Facebook, Twitter, Tumblr, Instagram, Pinterest, GetGlue, YouTube and abcfamily.com) with its built-in fan base and central mystery.

“There is definitely something out there that has bonded these five kids,” Goldstick says. “I hope people will be just as engaged and want to be speculating via Twitter and other boards about what the hell is going on in this town.”