Pretty Little Liars season 7
Pretty Little Liars season 6 finale introduced Jessica DiLaurentis' identical twin Mary Drake as the new antagonist of the show Freeform

Freeeform has released the first promo for Pretty Little Liars season 7 through the show's official Instagram account and the clip hints at a scarier next season of the popular thriller. After the end of season 6, show creator Marlene King had promised huge mysteries to be unravelled in the next instalment and from the promo it appears that the show will live up to them.

The liars, Emily, Aria and Spencer appear terrified in the trailer as they try to dig a grave. "I don't know if I can live with this," says a visibly upset Emily (Shay Mitchell). "There is no other way, Emily," answers Spencer (Troian Bellisario) while making a shocking statement. "When it ends like this, it's called murder."

The season 6 finale ended with plenty of questions, including who kidnapped Hanna (Ashley Benson) and if she is still alive and what lies in store for Alison (Sasha Pieterse).

Ali was shown entering a mental institution after doubting her sanity as she kept seeing her dead mother Jessica Dilaurentis. However, later it was revealed that Jessica's twin and CeCe Drake's mother Mary Drake plotted the entire drama with Elliot Rollins to exclude her from Dilaurentis's estate and avenge CeCe's death.

But will they stop their evil plotting after Ali enters the same hospital where Charlotte was being treated for mental problems? It appears not as the freshly released promo hints that Ali will endure severe mental torture due to Mary and Rollins.

As far as Hanna's status is concerned she appears very much alive but the threat of AD (the newly declared Uber A by the show creator) still looms large and, in an attempt to save Hanna, Aria, Emily and Spencer, may commit the biggest crime of their lives.

King has previously hinted that there will be a "big reveal in almost every episode that will blow fans' minds," and the promo promises the same. It remains to be seen how Pretty Little Liars season 7 will move ahead with the liars' latest adventure.

The show will premiere on 21 June at 8/7c on Freeform in the US.