Somewhere in New Zealand tonight a little boy may come to his parents, like he has before, like generations of kids have before, and say, "Mummy, Daddy, where do I come from?"
It's a fair enough question for a four-year-old. But for this little boy, the answer is complicated.
He is Baby X, who earned the nickname Nemo because he is the subject of an IVF surrogacy mix-up.
He's now being brought up in New Zealand, the loved second child of a Kiwi family. But the truth is no one knows who his real biological parents are or where he really comes from.
"We do talk to him with regards to how kids are made and things like that," Father X told us. "The term we use is that he did not come from Mummy's tummy; he came from another mummy's tummy. From his point of view, we believe that he still thinks, he is of the opinion, that he is our son like our first son. We treat him no different. He gets told off if he does something wrong. He gets praised if he does something right and everything in between."
The heart-breaking story of Baby X, which screens tonight on 3D at 9:40 pm, has been a long time in the making. The parents, understandably, were very reluctant to go public. They are desperate to protect the identity of their children. Who could argue with that?
But in the end, their desperation to find out who the biological parents of Baby X are, and what happened to their embryos, made them decide to speak out (without revealing their identities).
They also agreed to allow us to go to Thailand to, in their words, shake some trees, to see what we could find out. We made some breakthroughs, which you'll see in the story tonight. But there are still outstanding questions.
So Father X asks that if you know anything, particularly if you had IVF treatment at Chiang Mai Ram Hospital or Kullapat Clinic since July/August 2010, please contact us so we can put you in touch with him and his legal team.
Remember, at that time, Thailand had a thriving international surrogacy industry, so those people could be anywhere in the world, including New Zealand.
The international component of this case underlines what surrogacy and adoption specialist Dr Rhoda Scherman, of AUT's psychology department, told us in an interview.
She points out that surrogacy is so comparatively new that experts and intending parents need to look to adoptions for guidance, for instance around what questions the children of surrogacy arrangements might have when they grow up.
"They're going to have questions and I think we have a mandate to be able to answer them," she told us.
"In adoption we can see that those questions are, 'Where am I from?', 'Who do I look like?', 'Where do I get my ability to play the piano?'."
She urges the rest of us to not judge how couples choose to have children.
"That's at the heart of the debates, reproductive freedom and what that means and how they can go about creating a family."
Dr Scherman believes there needs to be an international set of regulations to prevent cases such as the Baby X situation, where the child could have ended up stateless.
"Different countries have different definitions for what parentage is. New Zealand for instance says whoever gave birth is the parent. India says the commissioning parents are the parents, not the surrogate. France for instance has outlawed any surrogacy."
In the case of Baby X, the parents were urged to abandon him, to walk away and leave him to an orphanage.
They refused, and fought for him through the courts, eventually adopting him through a fraught process involving lawyers in Thailand and New Zealand.
All for the love of a child – a child they are determined to be able to answer some day when he asks: Where do I come from?
If you need help with surrogacy or adoption, you can contact the ICANZ organisation.