Netflix's 'I Will Find You' Ending Explained: Is Theo Actually Sam Worthington's Biological Son?

In the final episode of Netflix's I Will Find You, Theo is revealed to be Matthew Burroughs, the missing child at the centre of the series, and the show leaves little room for doubt about the paternity twist. Theo is the biological son of David Burroughs, the wrongly imprisoned father played by Sam Worthington, not Hayden Payne, whose obsession drives the ending into chaos.

The series begins with David in prison for the murder of Matthew, who was believed to have died in his own bed at the age of three. That certainty starts to crumble when journalist Rachel Mills, played by Britt Lower and also the sister of David's ex-wife Cheryl, visits him with a photograph taken at Six Flags. In the background is a boy who looks exactly like Matthew, complete with the same birthmark on his cheek.

From that point, the show stops being a closed case and starts pulling apart the machinery that made it look solved in the first place. David escapes with help from prison warden Philip Mackenzie and Adam, the warden's son and a police sergeant, because he is convinced Matthew is still alive. Rachel follows the trail to Berg Reproductive, a Boston fertility clinic linked to the powerful Payne family. That is where the finale finally answers the Theo question.

'I Will Find You Settles': The Theo Twist

The key reveal is straightforward once the noise clears. Cheryl had been treated at Berg, but she used Rachel's name to keep the appointment secret. Later, Cheryl says she discovered she was pregnant the day after the procedure, which confirms Matthew was already David's biological son. In other words, the clinic did not make Hayden the father, however much he believed otherwise.

That matters because Hayden's entire claim to Matthew rests on a false assumption. He thought Rachel was the patient at Berg and provided his genetic material believing he was fathering her child. Years later, after seeing Matthew with Rachel's family, he concluded the boy was his son. He was wrong, and the series is unusually clear about that by the end.

Gertrude Payne, Hayden's mother, confirms that a paternity test had been carried out, but she never told him the result. A small omission, you might say, except it wrecked several lives.

Theo nor the actor playing Theo is not literally Sam Worthington's son, because Worthington is the actor. But Theo, whose real name is Matthew, is the biological son of David Burroughs, the character Worthington plays. That is the truth the finale lands on.

How 'I Will Find You' Explains Theo's Past

The show also untangles the older crime that sent David to prison. The child found dead in the Burroughs home was not Matthew. It was Martin Bischoff, a Swiss boy who had previously lived in a Payne-run orphanage and vanished shortly before Matthew was presumed dead. Martin matched Matthew in age and appearance, and later blood testing confirms the body was his.

That revelation blows apart the official version of events. David's conviction had rested on a bloodied baseball bat, a neighbour's claim that she saw him bury it in a forest, and his documented history of sleep terrors.

But the neighbour's evidence turns out to have been false, given at the request of Nicky Fisher, a Boston mobster who wanted revenge on David's father Lenny, a retired police officer, after Fisher's own son died in prison. Hayden then killed Martin, placed the body in Matthew's bed and used the Payne family's reach to manipulate DNA evidence so the child would be identified as Matthew.

It is a mad amount of plot, frankly, but the emotional line survives. David was never clinging to fantasy. He was following the one thing everybody else had stopped looking for, which was the truth.

By the time David, Rachel and FBI agent Sarah Greer close in on the Payne estate, the series has stripped away nearly every official certainty that once made the case look neat. Hayden presents himself as an ally until Rachel finds Six Flags photos showing him holding Matthew's hand.

Worthington said the characters had been 'played for suckers all the way through,' and that betrayal works because Rachel is hit from two directions at once, by the conspiracy and by Hayden's personal history with her.

The last confrontation is ugly and abrupt. As David and Greer try to leave with Matthew, Hayden shoots his mother and flees with Rachel. He later pushes Rachel aside and tries to escape with the boy, only for David to catch him. In the struggle, Hayden shoots David. Greer orders him to drop the gun. He says Matthew was the best thing in his life. Rachel tries to talk him down, but when he turns the weapon on her, Greer shoots him dead.

David's final line, 'I found you,' lands because the show has earned it. Creator and showrunner Robert Hull said the ending works because of 'everything that came before,' not simply the final beat itself, and that feels right. The finale is melodramatic, yes, but not in the cheap way.

Eight months later, David's conviction has been overturned and the truth about Matthew's disappearance is starting to circulate publicly. Rachel publishes her account as a book. Cheryl now has a daughter with her current husband. Matthew is back with his family, although not magically fixed, and still struggles with his memories.

Lower said the final moment is less about romance than people who have 'been through hell together,' while Worthington called it an ending of 'gentleness and simplicity,' with hope left in the audience's hands.