Arrow

In the season four premiere, Oliver and Felicity must return home to help the team against attacks by "ghost" assassins led by Damien Darhk (NEAL McDONOUGH).

When an old family friend, Jessica Danforth (guest star JERI RYAN) tells Oliver and Thea she's going to run for mayor, the Green Arrow and Speedy vow to protect her.

Laurel (KATIE CASSIDY) talks Thea (WILLA HOLLAND) into returning to Nanda Parbat to ask her father (JOHN BARROWMAN) to resurrect Sara (CAITY LOTZ) in the Lazarus Pit.

Laurel deals with the aftermath of taking Sara to Nanda Parbat, while Oliver asks Captain Lance (PAUL BLACKTHORNE) for a favor.

When things take a turn for the worse with Sara, Oliver calls in a favor from an old friend who deals in the mystical, John Constantine (guest star MATT RYAN).

Felicity's frantic when she learns that Ray Palmer (BRANDON ROUTH) is alive and being held by Damien Darhk. Sara joins the team on a rescue mission for Ray.

Team Arrow's ongoing battle with Damien Darhk is complicated by a shocking revelation. Meanwhile, Thea's bloodlust returns and she loses control in front of Alex (PARKER YOUNG).

Vandal Savage (CASPER CRUMB) sets his sights on Kendra Saunders, forcing Barry to hide Kendra in Star City with Oliver and the Arrow team in part one of the epic crossover.

In Part Two of the epic Flash crossover event, Oliver and Barry hide Kendra Saunders and Carter Hall in a remote location while they figure out how to defeat Vandal Savage.

After the city is attacked again, Oliver makes a bold move against HIVE, but Damien Darhk retaliates in a brutal manner at Oliver's mayoral holiday party.

Oliver must deal with the devastating consequences of Darhk's last attack. Seeking revenge, Oliver goes on a brutal manhunt looking for Dahrk.

Diggle must learn to trust his brother Andy (EUGENE BYRD) when an enemy of their wartime past, an agent of the criminal organization Shadowspire, pays a visit to Star City.

While the team faces off against a villain named The Calculator (TOM AMANDES), Nyssa al Ghul (KATRINA LAW) makes her move and Roy Harper (COLTON HAYNES) returns to Star City.

While Thea battles her blood lust and Malcolm steps in to help his daughter, Oliver receives an offer from Nyssa that is hard to refuse.

Oliver and the team uncover HIVE's plans to take out Team Arrow once and for all. Meanwhile, Oliver feels guilty, before his wedding, that he hasn't told Felicity about his son.

Realizing he needs help battling Darhk, Oliver calls in an old friend – Vixen (MEGALYN E.K.), who summons her animal powers to get a lock on his location.

A heartbroken Cupid (AMY GUMENICK) returns to Star City to destroy anyone in love, so Oliver and Felicity pose as bait on their "wedding day."

Brie Larvan aka the Bug-Eyed Bandit (EMILY KINNEY) breaks out of jail and sets her sights on Felicity. Oliver turns to a surprising ally to help Team Arow save the day.

Oliver and Diggle learn that Merlyn is going to break Darhk out of prison. Meanwhile, Laurel gets a surprising offer and Felicity has a heart-to-heart talk with Curtis.

Oliver and the team struggle to come to terms with Laurel's death. Meanwhile, Lance refuses to believe she's gone and asks Nyssa to help bring her back.

As Oliver and Felicity look for a magical solution to defeat Darhk, a vengeance-driven Diggle gets a lead on Andy's whereabouts and heads off to confront his brother.

When Team Arrow learns what Damien Darhk's devastating next move is, Felicity realizes she needs to ask her father, Noah Kuttler (TOM AMANDES), for help.

Following the shocking events in the previous episode, Oliver and Diggle race to rescue Thea, while Felicity, Curtis and Noah join together to stop Darhk.

In the season four finale, Oliver teams up with a surprising force in an attempt to stop Damien Darhk and his magic once and for all.