20. 'Til Death Do Us Part

Complete story — includes the ending

A year later, Aria and Ezra prepare to be married while Alison and Emily have twin daughters, Grace and Lily but Alison soon proposes to Emily who accepts. Before the wedding, Ezra goes missing and Aria becomes frantic that after finding out about her fertility, he had abandoned her. On the other hand, Spencer is kidnapped by Mona working for A.D. and brought to a bunker. There, A.D. is revealed to be Alex Drake, the identical twin sister to Spencer and that she met Wren and in turn met Charlotte who she was close with. After Charlotte's death, she returned to Rosewood but became jealous of her sister's life and impersonated Spencer while vowing revenge. Wren is revealed to have died after Alex killed him because he tried to stop her plan and that he fathered Alison's twins. With the help of Mona, the group find Ezra and Spencer and they manage to escape from an axe-wielding Alex who is arrested alongside Mary, after she tries to convince Toby that she is Spencer. Mona is revealed to have kept Alex and Mary in her personal Dollhouse, while the Liars are gathered one last time before Aria leaves for her honeymoon. Addison's friends are having a sleepover in Rosewood, but finds Addison has gone missing, ending the series.