UPDATE: New Extended Promo For ARROW Season 3 Episode 21: "Al Sah-Him"

THE LEAGUE OF ASSASSINS SETS THEIR SIGHTS ON NYSSA - Oliver (Stephen Amell) goes through a rigorous transformation. The League of Assassins sets their sights on Nyssa (guest star Katrina Law), who is back in Starling City training Laurel (Katie Cassidy). When Nyssa realizes they are coming, she arms up to face them alone but Laurel asks Felicity (Emily Bett Rickards) and Diggle (David Ramsey) to help protect her new friend. Thor Freudenthal directed the episode with story by Beth Schwartz and teleplay by Brian Ford Sullivan & Emilio Ortega Aldrich (#321).

Determined to right the wrongs of Starling City and sworn to bring justice to those who have failed it, Oliver Queen (aka The Arrow) — with the help of his iron-fisted right hand, John Diggle, the tech-savvy Felicity Smoak and the newest member of the team, Roy Harper — narrowly defeats the vengeful Slade Wilson, his onetime ally and mentor on the island of Lian Yu. But like all wars, there are casualties. Sacrificing herself for her children, Moira Queen falls at the hand of Deathstroke, sending Oliver’s sister, Thea, into self-imposed exile with her biological father, Malcolm Merlyn. In Season Three, Oliver faces an even greater threat, when another lethal face emerges from his dark and tortured past – Ra’s Al Ghul!