In an all new Pretty Little Liars, 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.

Watch “That Girl Is Poison,” airing Tuesday, July 10th, at 8:00 – 9:00 PM ET/PT.

Photos: ABC FAMILY/ERIC MCCANDLESS