Nyssa Al Ghul returns to Star City to warn Thea that a group of renegade League of Assassins members are planning to attack her. This group, led by Athena, is intent on finding a mysterious box that Malcolm left behind and will stop at nothing to get it. Nyssa helps Oliver come to a life-changing realization.

When you go outside the city white people be acting different. That's why I can't even go to Marietta. Too weird.

The crew struggles to come to terms with an injury to one of their own; a temporary replacement must be dealt with; Boden ponders some interesting news; Kidd has a hard time keeping a secret.

Arkham's "finest" give Gordon and Bullock a run for their money, as they hatch a plan to escape the asylum. Meanwhile, Bruce devises his own strategy to thwart their plans. Also, Barbara gets an offer she can't refuse.

April’s crisis of faith is challenged by a patient she treats who is a rabbi, and Meredith treats a patient who is a transplant surgeon from another hospital.

When Charlie is taken into custody for the hijacking of Air Force Two, Quinn is faced with an important choice. Meanwhile, Cyrus is pulling the strings behind closed doors and sets out to recruit Jake to join him on his quest for the White House.

Sam, Dean and Castiel are transported into the animated world of Scooby Doo where they join forces with the Scooby gang to solve a ghostly mystery.

The new district manager decides to make some cuts to save money. Mateo struggles to prove his skills on the cash register.

Penny gets the opportunity to host Bill Gates at work when his company wants to partner with her pharmaceutical company. Also, Leonard, Koothrappali and Wolowitz do everything in their power to meet him, while Sheldon thinks he is the victim of an April Fools prank.