SPOILER ALERT: This story contains details of the season finale of Pretty Little Liars.

An average of 2.3 million viewers — 1.3 million of them in the demo — tuned in to ABC Family’s deadly Pretty Little Liars season finale. By “deadly” we mean the finale became the second most-tweeted TV series telecast of the summer, behind only its summer premiere — driven by the #RIPMona hashtag. Mona Vanderwaal, played by series regular Janel Parrish, got bumped off just as she was about to reveal something big — by someone sporting long hair, and black hoodie. Parrish tweeted she’s now a flashback girl. The #RIPMona hashtag generated 339,000 tweets yesterday, including more than 200,000 tweets between 9 PM and 10 PM alone, making it the fastest-growing and biggest episode-specific hashtag Pretty Little Liars has ever seen.

Pretty Little Liars was Tuesday’s No. 1 TV telecast in women 18-34 and females 12-34. It was cable TV’s No. 1 telecast with women 18-49 and the No. 1 original cable TV telecast in adults 18-34, adults 18-49 and viewers 12-34. Pretty Little Liars stood as Tuesday’s #1 cable TV telecast at 8 o’clock for the 107th-consecutive original telecast in females 12-34 – each telecast since its June 2010 series debut – 59th in adults 18-34, 66th in women 18-34, 62nd in women 18-49 and 70th in viewers 12-34.

ABC Family noted that, on Instagram, Pretty Little Liars has become the No. 1 most-followed scripted show, with more than 1.1 million followers, topping No. 2-ranked Netflix’s Orange is the New Black (836,136).