The final episode of "Arrow" season 4 ended with Oliver being sworn in as the interim mayor, so he temporarily abandons his bow and cowl and takes a leave as a hero.

Titled "Schism," the episode featured Reiter and Taiana coming face to face with each other in a showdown. During the fight, however, both of them die, leaving Oliver torn. After the fight between Reiter and Taiana which left both of them dead, Oliver began to experience some internal scrimmage as he pondered on whether it was his light side or dark side that was getting the better of him. The reflection came as he found himself endlessly murdering a good number of people.

In the course of his contemplation, Amanda Waller was there to remind him about justice. According to her, killings are sometimes necessary to move ahead in the path of justice.

Meanwhile, Oliver faces Darhk in a brawl. After Oliver succeeded in putting the villain down, Team Arrow began to celebrate their huge win. As the heated ruckus between Team Arrow and Darhk and the Ghosts finally ended, everyone in Team Arrow was already of a mind to leave the team to start a peaceful life away from the hustle and bustle of the city, except Felicity.

Towards the end of the episode, Oliver delivered a moving speech after being sworn in as the interim mayor, giving hope to his constituents amidst the growing anarchy in the city.

"Arrow" season 4 centered on how Oliver managed to frustrate the plans of Dahrk, who is determined to destroy the world.