Wren was in season 1 episode 4 and then comes back in season 2 episode 2
Lucas and Hanna kissed in Pretty little liars in season 1 episode 12.
episode 13 season 1
The last episode of season 2! Episode 25.
you find out in season 2 in the season finale :)
Season 1 Episode 1 ( Pilot )
Season 2 episode 9 :)
The last episode but there is more of A to come!
the computer
Episode 1 or 2 I believe of season 1.
Season 2, Episode 04, titled "Blind Dates"
You can watch PLL (Pretty Little Liars) season 4, episode 21 at TV Muse.
There was no Halloween episode of Season 1. It ran from June to August 2010 and did not resume until January 2011.