WARNING: The following contains spoilers for The Third Day Episode 6, "Last Day -- The Dark," now airing on HBO.

HBO's The Third Day concludes its first season by confirming what happened to Jude Law's Sam after he took over as "Father," the leader of Osea. It's revealed that he's been reclusive, causing the unstable Jess to want their daughter to become the new queen, which is why the civil war's taking place.

However, with Sam trying to now protect his wife, Helen, and their daughters, Lu and Ellie, another issue is addressed over the fate of Nathan. Initially, many thought Nathan was a ghost roaming the island, only for it to be confirmed he was hidden on Osea after being kidnapped years ago. Well, that turns out to not be the case, and the truth actually leaves fans with an intriguing question.

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When Sam takes Helen to meet Nathan, she's shocked, leaving fans to think it's from him being alive. It turns out, she's faking it because when she gets Sam alone she's seething, indicating he's too old to be their son. Nathan would be 16, while this boy's barely 10, not to mention he isn't of mixed ethnicity. Sam's in denial, but Helen thinks he's delusional, so she just wants the money from their savings Sam left with nine months ago.

As Jess' faction begins scouring the island in the coup, Mrs. Martin, sensing time's running out, breaks down and confesses the truth herself. They arranged to have Jason's son killed and his body swapped for Nathan, and the immigrant Goltan did hide Nathan to bring to them. However, when Nathan tried to escape Goltan panicked and killed him. They found Goltan days after, wrecked from staying with the dead boy as he didn't know what to do, leaving Mrs. Martin to dump the real Nathan in the sea off the causeway.

RELATED: The Third Day: Epona's Role on Osea - and Her Final Fate - Are Horrific

It destroys Helen to hear about the botched kidnapping, knowing her son was robbed of his life by these selfish natives who felt they could groom him to be king. As for Sam, Helen reams into him, admitting Sam is at fault because he was on the phone for a half-hour with a fling, which allowed the boy to be abducted. Sam's psychosis, as he has Jack the Ripper's blood in him, fooled him into believing Nathan's still alive when really, he's as much to blame as Mrs. Martin. This guilt is also why Sam took the money, so Helen couldn't move and they'd have to remain in their old home in case Nathan ever came home, which suggests Sam knew that corpse wasn't his son. Furthermore, it explains why every year he'd go back to the mainland, maybe thinking he'd find Nathan.

Unfortunately, Helen's too busy trying to stay alive to exact revenge on either of them, but later on, after Sam gets her the money from the island's sinister church, the fake Nathan stuns everyone with an admission of his own. While Helen escapes with the girls, Sam opts to stay behind with "Nathan" -- who's a descendant of Sam's mad grand-uncle and possibly the product of the old man raping Epona. But as Helen departs, the boy tells her he forgives her for saying years ago she never wanted to have him when they fought. Helen's stunned because she only told Osea's Cowboy about this, not even Sam knew. And seeing as the Cowboy wasn't in contact with Nathan, fans are left wondering how could he know about this argument. Sadly, Helen has to depart without an explanation, but she leaves wondering if her son's soul is now in this child's body.

HBO's The Third Day stars Jude Law, Naomie Harris, Katherine Waterston, Nico Parker, Charlotte Gairdner-Mihell, Paddy Considine and Emily Watson.

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