One of the four girls indeed finds out the identity of A while the person is in action but she is snapped shut before telling the other three.
"Pretty Little Liars" wrapped up the first half of season 1 without really unveiling the identity of 'A'. The big question's answer was only known to one of the four best friends, Hanna. But just when something good is about to happen, something bad gets in the way. Hanna was hit with a car before she told the other girls, and viewers.
The culmination of the mystery all happened during Mona's glamping (glam camping) party which includes a scavenger hunt. 'A' has challenged the girls to find out about him/her during the game and Hanna wanted to make the most of it. Together they found out that their missing friend Alison was involved with Spencer's boyfriend Ian when they saw their names craved on tree bark.
Meanwhile, Aria got a text from Mr. Fitz to meet him secretly. They had a passionate reunion while Hanna witnessed it from afar using binoculars. Coincidentally, Hanna also saw a hooded figure approaching Fitz's car and writing "I see you" on the windshield. She quickly texted her friends, "I know who A is" and asked them to meet in the parking lot. As Hanna approached the other three who have been waiting, a car came out of nowhere and struck her.
Later, 'A' gave Aria a text, "She knew too much. A." The season ended with Emily's scream and a shot of Hanna's lifeless body.
The remaining episodes of the ABC Family drama will debut in September. In an interview with Us Magazine, Troian Bellisario revealed about the continuation, saying "They get blackmailed by someone that can possibly be their dead best friend. You can never fully rest, and so that's what's so great about it."