Karl T. Wright

When NASA reschedules Howard's mission and puts his wedding plans in jeopardy, he's forced to face his fears and Bernadette's dad (guest star Casey Sander). Meanwhile, Leonard says something surprising to Penny in the bedroom.

Bailey treats a young mother battling breast cancer; Derek learns more about Mark and Addison's relationship; the interns defend a resident's competence at a staff meeting.

Paul stands in the way of Susan receiving a kidney transplant; Tom passes up a lucrative job to continue working with Carlos; Andrew's alcohol consumption increases, worrying Bree.

Aria, Emily, Hanna and Spencer have made a crucial mistake — they told someone about “A” and now they must pay the price. With the clock ticking and “A” calling the shots, the girls are sent on missions to do “A’s” bidding in order to save their trusted confidant. Each mission will ultimately lead to what the four liars want the most, but at a costly price to their loved ones and themselves. Can Aria, Emily, Hanna and Spencer go through with their given tasks, or will they ignore “A” to save those around them from being hurt? And, ultimately, will this matter when all is said and done? Nothing is ever as it seems in Rosewood, PA.

Patrick Jane and the CBI team are called in to investigate the murder of a convict who served nine years for rape and murder, but was recently released on DNA evidence. Jack Coleman (Heroes) guest stars as the husband of the convict’s victim.