Purgatory (Arrow)

"Purgatory" is the seventh episode of the eighth and final season, and 167th episode overall of the American television series Arrow based on the DC Comics character Green Arrow, revolving around billionaire playboy Oliver Queen as he returns to Starling City (later renamed Star City), after having been shipwrecked for five years, and becomes a bow-wielding, hooded vigilante who sets out to fight crime and corruption.

The team learns that Lian Yu, the island Oliver Queen was stranded on, has been giving off an immense amount of strange energy and Lyla Michals tasks William Clayton with creating a device to harness it, while the plutonium is being transported by Dinah, Rene and Roy Harper.

Diggle, Lyla, and Connor rescue Dinah and Rene, while Oliver and Laurel retrieve the plutonium.

However, they are confronted by Edward Fyers, Billy Wintergreen and Yao Fei – deceased figures from Oliver's past who were all revived by the island's supernatural energy.

Meanwhile, Diggle's party finds Roy, whose right arm is pinned; forcing Connor to amputate it, after William completes the weapon, Lyla activates it and transforms; absorbing the island's energy and causing its revived inhabitants to disappear before entering a portal.

She later returns, now calling herself a "harbinger of things to come", and informs Oliver and Mia Queen that the Crisis has begun as the sky turns red.

[4] "Purgatory" stars Stephen Amell, David Ramsey, Katherine McNamara, Ben Lewis, Katie Cassidy, Rick Gonzalez, Juliana Harkavy, Joseph David-Jones, and LaMonica Garrett as Oliver Queen, John Diggle, Mia Queen, William Clayton, Laurel Lance (Earth-2), Rene Ramirez, Dinah Drake, Connor Hawke, and as both the Monitor and the Anti-Monitor.

The scene leads directly into the Supergirl episode, "Crisis on Infinite Earths: Part One".