Jenna's extravagant birthday party seems to be too good to be true and Aria, Emily, Hanna and Spencer think something else might be up - especially when it turns out that Garrett is getting a pass out of jail to visit his ailing mother on the same night. The timing can't just be a coincidence; the Liars are convinced it all has to do something with "A." With Emily getting an insiders' view working the party, Aria working the crowd as a party-goer and Spencer staked out at the hospital, what could go wrong? The answer is - everything. Meanwhile, Hanna's wallowing through heartbreak leads her to a shocking discovery, in "That Girl Is Poison," an all new episode of ABC Family's hit original series "Pretty Little Liars."