The Missing series 2 episode 4 recap: is there a third missing girl?

I'm worried viewers will find it too much, that every switchback in the road of this European mystery will just make people sick and tired of the whole journey.

The Missing series 2: YOUR best theories

And that would be a shame, because there's a tantalising trail being laid here, even if the revelations of episode four has us scratching our heads all over again.

So, what questions do we need answers to this week? Episode four spoilers to follow.

Who is the third girl?

We're no closer to solving the whole 'Is Alice Webster really Sophie Giroux?' puzzle, but instead of offering us another clue, this week's episode gave us a whole new picture.

To recap. In episode three Gemma Webster found, while searching through her rollercoaster photos, a picture of a girl (below) that looked exactly like the person who walked back into her home claiming she was 'Alice Webster' (I'll use quotation marks to make it clear we're still not sure).

However, Gemma insisted that her real daughter was the girl sitting beside her. Like Julien, she has never really believed that the person who came back after years in captivity was Alice.

But in episode four, we find out there's another significant picture from the rollercoaster, of a girl in glasses and wearing a necklace sitting just behind the other two (above). She looks very similar to the dead 'Alice', and that necklace could be (it's too blurry too see) the same one that 'Alice' was seen playing with while she was sleeping in the shed in episode 2. Honestly, we're trying our best to be helpful – take a look for yourself.

The switch to Switzerland in the final scene made things even more complicated. Remember from episode three, this is the location where the suspicious campervan is pitched up, the same one we assume took Alice all those years ago. The final scene showed a waiter making a pass at a woman sitting in a cafe. She refused, saying (chillingly, given the circumstances), "I'm afraid I'm taken." She turned round – and we see that she is the spitting image of the dead 'Alice'. Huh?

How do all these people link up? Is the person alive and drinking coffee in Switzerland Alice, Sophie, or another girl entirely? Was the girl who killed herself in the fire Alice after all, despite Julien and Gemma's suspicions? I can't pretend to have have any real clue at this stage beyond the necklace, but hopefully this makes it a little bit clearer where we stand.

What about the DNA results?

Yes, of course! The test that detective Julien (along with the rest of us sitting at home) had called for was finally carried out – and it didn't give us the answer we expected. Instead of confirming Julien's suspicion that the dead girl wasn't Alice, the results tell us that her DNA did indeed match that of father Sam Webster.

What should we make of that? Were we too quick to believe Gemma's 'mother's intuition' and Julien's suspicions, over the faith of Dad Sam and brother Matthew?

Perhaps – although the fact that in the present day Julien is still searching shows that there's still more to be learned. Also, this episode featured an odd present day conversation between Sam Webster and Brigadier Adrian Stone.

Stone: “Alice Webster. Yes. I wouldn’t forget that, captain. I wonder if they’ll ever find out what happened to her...”

Was that Stone's dementia simply getting the better of him? Had he just forgotten about the fire that killed Alice? Or, alternatively, was he letting slip that he knew the girl who came back wasn't Alice at all?

Here's just one suggestion, and it's an outlandish theory: could the girl who came back calling herself 'Alice' somehow have got out of the shed before it went up in flames? Perhaps the real Alice has been dead all along, and this is a way of getting rid of the body and making it look like suicide... As I say, just a theory.

Why did 'Alice' go to Henry Reed's grave before she killed herself?

This was the moment where we thought we had it cracked. The link between the missing girls and Henry Reed, and therefore the reason Julien had travelled out to Iraq to find his son Daniel Reed.

'Alice' captured on CCTV emerging from a florist's, hours before she kills herself

Unfortunately, the revelation of another girl threw us back into the dark, but at least this scene proves that Julien isn't on a wild goose chase. Henry Reed, good friends with the highly suspicious Brigadier Stone, also shared a close bond with a captive girl, so much so that she took flowers to his grave before killing herself. Why?

Maybe someone can help us with that question...

What more can Mirza Barzani tell Julien?

Julien learned from Daniel Reed that his father was paying large amounts of money to a mysterious man called Mirza Barzani. Julien tracked him down to a museum, and asked him why Reed was making all those payments.

"Henry Reed made those payments out of guilt," Barzani said. "For what they did to my sister... she was only nine years old."

There's clearly more to come from this conversation next week, but even the beginning of Barzani's story sets alarm bells ringing.

"In 1991 I was just a boy. That was when they came to my village... Henry Reed and his Army friend, a man called Stone.”

Stone again. Stone, the man who threatened 'Alice' to keep her mouth shut – and, quite possibly, forced her to pin the blame on butcher Kristian Herz. Stone, the man who in his state of confusion tells his daughter about a girl he used to know with "alabaster skin". What did he and Henry Reed do together?

What else have we missed?

Oh, plenty, of course. We could talk about what happened to Eve and her baby, and whether Matthew caused a miscarriage after he shoved her to the floor.

We could talk about Julien hallucinating and seeing his wife, and wonder how much his brain tumour is affecting his powers of deduction. In episode three, when asking about the DNA test, he said, "All I want is the certainty that science offers". Well, he had that, and it doesn't seem to have made a blind bit of difference.

We could talk about the weird situation Gemma has found herself in, working with the woman who is having an affair with her husband. We could talk about Dad Sam, who cruelly blames his own son for the death of his 'daughter' just when he's most vulnerable.

In trying to keep the central mystery clear in our minds, it's easy to forget the emotional trauma that each individual is going through.

That, of course, is precisely the point.