Some Emmerdale viewers were puzzled this week as they learned exactly how Caleb Miligan discovered the truth about his parentage.
Fans have known for months that he is the secret heir of Frank Tate, and that his mother was Faith Dingle.
Faith fell pregnant after a fling with Frank, and ended up giving birth in prison before she gave him away.
Caleb grew up in a children's home and didn't know his family, even though he tried to reconnect with Faith and her children when he was a teenager.
Viewers have been wondering for months how Caleb knew he was the son of Frank, given he never met Faith and nobody else knew this information.
But the truth was revealed this week, as Caleb's revenge plan against Frank's ex-wife Kim Tate finally came to light as well as his identity.
Viewers learned that Caleb found out who his real father was from a letter, that was written by his mother Faith and passed on to him.
But some fans were confused by this, wondering if the letter meant they were in contact and whether Faith knew his whereabouts.
After Faith's death in October last year, she left a letter with a final message for her family to be read out at her funeral.
Hearing Caleb had received a letter from Faith, some viewers appeared to believe it was sent to him before her death, explaining everything about Frank.
There's also the fact Faith had not mentioned Caleb at all during her time on the show, despite appearing to reach out to him in secret.
Taking to Twitter, one viewer questioned: "Faith left Caleb a letter but never talked about him once before dying, she never wanted to check on him, see him."
Another fan wrote: "Caleb talking about Faith's letter," with a shocked face emoji, while a third fan said: "Faith knew she had a child with Frank Tate and it was never mentioned in all of the years she was in the show? Who is writing this crap??"
The letter was only given to Caleb when he was around 40 years old, but it was written by Faith long before then, and long before her death.
In fact, Faith wrote the letter after Caleb was born and gave it to a nun who worked at the children's home Caleb went to.
Faith wrote the letter for her son knowing they would part ways, and never got into contact with him after this point - with Caleb claiming she didn't want him.
The letter was not passed onto Caleb until years later, when the nun handed the letter to Caleb after tracking him down.
It was this letter that told him everything he needed to know about Frank, while all the information about Kim and Frank's death came from former character Graham Foster, who worked for Kim.
So this story appears to confirm that Faith and Caleb never met or had contact, and it seems Faith did not try to reconnect with her son.
Later in life when Caleb got the letter and found out about Frank, he came into contact with Graham and the rest is history.
Emmerdale airs weeknights at 7:30pm on ITV1 and ITVX, with an hour-long episode on Thursdays.