By the end of the hour, the files might be deleted, but the shadows are only getting longer. In the world of "A," you can delete the data, but you can’t delete the history.
The episode ( Season 2, Episode 20 of Pretty Little Liars ) centers on the Liars' frantic race to outmaneuver the police and "A" after Detective Wilden gains access to Caleb's laptop.
Here is a blog post concept exploring the episode's themes of technology, loss of control, and the "Vivian Darkbloom" mystery.