Pretty Little Liars fans have told of their shock after the show’s mystery was finally solved after seven years.

The US drama wrapped up with the revelation that the mysterious evil “AD”, who had been tormenting Aria, Alison, Emily, Spencer and Hanna, was actually Spencer’s twin sister Alex Drake.

Viewers flooded social media with messages saying they were left stunned by answer.

“MIND BLOWN…I did not see that coming! #PLLEndGame still in shock and can’t believe it’s all over, I want more!” one fan posted on Twitter.

“I’m so stunned I don’t even know what to tweet,” said one.

Another viewer wrote: “I seriously am still in shock over the FINALE #PLLEndGame. I didn’t except it to end like this.”

After the dust on the big reveal had settled, many viewers said they were sad the show was all over.

“Is it bad that my heart is literally broken bc pll has ended? I’m devastated,” tweeted one upset fan.

“Beyond devastated that #PLL is over, but wow, what a finale!” said another.

The stars of the series said their goodbyes on social media.

Lucy Hale, who played Aria, posted a picture of the cast on Instagram.

She wrote: “For me to be speechless says a lot, but I’m finding it hard to find the words to express my gratitude to every single person that made this show a success. Sometimes simple is better and I just want to say… I will miss you Pretty Little Liars.”

Troian Bellisario, who starred as both Spencer and Alex, posted a lengthy message saying it had been “a rare and beautiful gift”.

Today closes the chapter on a very significant part of my life. A chapter I had never imagined or even dreamt of having written. When I left collage I thought I was headed to NYC (hopefully for some jobs on stage) Little did I know life was actually taking me to Rosewood, Pennsylvania. Where they insisted I would need to do high school for about 6 more years. Life (for reasons that will continue to reveal themselves to me ) made me a Pretty Little Liar. For 8 years. For around 10,000 hours of my life it asked me to be Spencer Hastings. It took me to days where I couldn't stop laughing, and nights when I wished I could have been sleeping in bed, instead of running in the wet and cold for the umpteenth take at 5AM but somehow we made it through and we had fun even then. Every moment with this cast and crew, in this town, every breath I took with Spencer, every text, dead body, new suspect, terrifying scream, new relationship and "kisses, A" taught me something extraordinary. It taught me patience, and how to approach my craft, how to direct, produce, it taught me about collaboration, experimentation, risk, friendship, family, empathy, sacrifice and above all LOVE. Being Spencer Hastings in this crazy world is something I still don't quite understand, but I know it was a rare and beautiful gift. A gift that will continue to give for the rest of my days on this Earth. And I wanted to say THANK YOU to all of the people who gave it to me. To all of the people who believed in me and made it possible, to my friends and family who loved me through it and above all to YOU, the fans, who watched, who tweeted, and posted, who theorized, swooned and screamed. We got a lot out of this experience, but I would have been nothing without you. Thank you and I love you all very much. (I love you too, Spencer, you weirdo). Enjoy tonight. I know I will. #pllendgame #spencerhastings

A post shared by Troian Bellisario (@sleepinthegardn) on

She wrote of the experience: “It took me to days where I couldn’t stop laughing, and nights when I wished I could have been sleeping in bed, instead of running in the wet and cold for the umpteenth take at 5am but somehow we made it through and we had fun even then.

“Every moment with this cast and crew, in this town, every breath I took with Spencer, every text, dead body, new suspect, terrifying scream, new relationship and ‘kisses, A’ taught me something extraordinary. It taught me patience, and how to approach my craft, how to direct, produce, it taught me about collaboration, experimentation, risk, friendship, family, empathy, sacrifice and above all LOVE.”