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.

The last Semi-Final round begins and Landon Swank, Kinetic King, Summerwind Skippers, Gymkana, Snap Boogie, Smage Bros. Riding Shows, Fatally Unique, Landau Eugene Murphy Jr., Silhouettes, Professor Splash, Steven Retchless and Anna Graceman perform to impress America to get the last 5 spots in the Top 10 and one step closer to the $1 Million and a Headline Act in Las Vegas!

When Rich invades Ashley's territory in the jewelry and loan department, she puts him in his place. Then, Seth negotiates hard for high-value jewels, but when the customer starts abusing his girlfriend, things really heat up. Plus, Les eyes a rare piece of memorabilia from a famous movie and ignites a bidding war on the sales floor. And, Rich crosses the line and sends Ashley through the roof. With neither of them willing to back down, will Ashley find common ground or send Rich packing?

Bobby loses his composure during a hockey game between the allied forces; a prank goes awry for Simon; and the investigation into a suicide bomber raises ethical questions for Pedersen.

As the seniors prepare to graduate, Holly J. prepares for her kidney transplant, Fiona deals with some difficulties, and Katie considers taking things to the next level with Drew.

Rebecca takes over triage when Col. Marks is injured in an explosion, and the situation leaves Rebecca with a judgment call to make.

The legendary Gatling gun is introduced. But first the competition travels back to the Old West for a team challenge with a historic pistol. To stay in the competition two marksmen shoot it out with a firearm considered by many to be the world's first practical machine gun.

A mock DUI event is held at the school, and Jenna gets cast as the victim. Meanwhile, Jake and Matty vie for her attention.

Fiona gets her house in order by hiring a new employee and hatching a scheme with her husband to expose the impostor in their family.

Actor Alec Baldwin; former professional football player Joe Namath; Lenny Kravitz performs.

Jeff Bridges, Nicole "Snooki" Polizzi

Chi McBride, Ariel Tweto

After learning about 'spiriting' from Robbie, Suzy and Henry discover that they can meet, and touch, on a new metaphysical plane of existence. But spiriting has consequences.

Lisa finds her self-esteem taking a turn for the worse after her smock top is mistaken for a baby bump. Kate is concerned after she learns that her husband's death is being investigated.

For many centuries humans have dreamt of reaching the centre of the Earth. Scientists are bow uncovering a strange and alien world that lies 4,000 miles beneath the ground.