When the Phone Rings: Ending Explained

The man called Sa-eon is not Sa-eon

The finale, episode twelve, confirms the show's central deception: the presidential spokesperson known as Baek Sa-eon is an imposter who took the name and place of the real Baek Sa-eon. The genuine Sa-eon is the biological son of Chairman Baek Jang-ho, hidden away for years because of his sociopathic nature. As a child the real Sa-eon mutilated fish, then cats, and eventually killed children at an orphanage, with his grandfather covering up the crimes and hiring a man to dispose of the bodies. The man Hee-joo married is the boy who survived and replaced him.

The lake and Hee-joo's brother

Chairman Baek Jang-ho is exposed as the architect of the tragedy that has shadowed Hee-joo for years. He orchestrated the incident that killed her younger brother, taking the boy to a lake and attempting to drown him. The man who would later live as Sa-eon survived that drowning. Jang-ho reveals this buried truth directly to the fake Sa-eon in order to destabilise him psychologically, weaponising guilt and identity against the man who built a life on the stolen name. The revelation reframes the marriage at the centre of the series and the silence that has defined it.

The standoff and the reckonings

The conspiracy unwinds through a series of fates. The real Baek Sa-eon, still pursuing his campaign to ruin the man who took his place, is shot dead by police during the standoff that ends the penultimate episode. Shim Kyu-jin is convicted of smothering Jang-ho with a pillow and asks for the death penalty after learning her own son is dead. Park Do-jae, who had kidnapped Hee-joo, is arrested for the abduction but is eventually forgiven and rehired by Sa-eon, closing out the threads of blackmail and violence that ran through the season.

Argan and a real marriage

Crushed by the discovery that Jang-ho killed Hee-joo's brother, the fake Sa-eon disappears to the war-torn country of Argan as a form of self-punishment, donating his inheritance to charity and vanishing for six months. Hee-joo eventually follows a clue, travels to Argan to find him, is kidnapped by rebels, and is rescued by Sa-eon himself. The two reconcile and decide to remarry for real this time, with him taking a new legal name so the union can finally be legitimate. The finale skips ahead to the remarried couple hosting an ordinary, peaceful lunch.

The Final Image

The remarried couple host a quiet lunch for friends, finally living the ordinary life they always wanted after the imposter takes a name truly his own.

Lingering Questions

Is the Baek Sa-eon that Hee-joo married the real one?

No. He is an imposter who took the identity of the real Baek Sa-eon, the chairman's sociopathic biological son. The man Hee-joo married is the boy who survived the chairman's attempt to drown him.

Who killed Hong Hee-joo's younger brother?

Chairman Baek Jang-ho orchestrated the lake incident that killed her brother and tried to drown the boy who became Sa-eon. He revealed the truth in the finale to psychologically destabilise the imposter.

Sources

• When the Phone Rings — Wikipedia
• When the Phone Rings Ending Explained — Screen Rant

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