The War Between the Land and the Sea episode 2 ending explained: What did Salt do?

Warning: Major spoilers ahead for The War Between the Land and the Sea episodes 1-2.

Doctor Who's long-awaited spin-off The War Between the Land and the Sea has arrived with a splash (sorry!) and given us plenty to mull over before new episodes arrive next week.

Episode 2 of the five-part series , titled Plastic Apocalypse, ended with the Earth in crisis and plastic raining down on the streets of Earth, with Salt and co turning things around on humanity, and forcing them to experience a little of what happens in our oceans and waterways every day.

So far, The War Between has introduced us to Russell Tovey's Barclay and Gugu Mbatha-Raw's Salt, with the pair forming an unlikely connection.

Now, as things get critical for humanity at the end of episode 2, aptly titled The Plastic Apocalypse, here's your breakdown of everything that's happened - complete with some intel from Jemma Redgrave (Kate Stewart) and Alexander Devrient (Colonel Christofer Ibrahim).

Want more from The War Between the Land and the Sea? Check out our chat with Redgrave and Devrient, which sees them break down that "risky" relationship reveal.

The War Between the Land and the Sea episode 2 ending explained: What did Salt just do?

The end of episode 2 sees Salt and the Homo Aqua (the Sea Devils) removing every bit of plastic from the oceans and waterways and causing it to rain down on the streets of Earth. In doing so, she exemplifies exactly what the Homo Aqua have been living with every day and turns it back on humanity, forcing them to live with the consequences of their actions in a very real way.

The first two episodes of the spin-off focus on negotiations between the two species after Homo Aqua emerged from the oceans and made their presence known to the whole world. Understandably, they were left enraged by the state of the oceans, particularly after two Homo Aqua were killed by humans, and after the loss of Salt's children and "scores" more, who died as a result of water pollution.

During negotiations at the Empress Hall (complete with a gigantic water tank), Salt stepped forward as the leader for the Sea Devils, and demanded that Barclay be appointed ambassador for humanity. Of course, Barclay doesn't exactly have any political experience - so UNIT have been feeding him a script in the negotiations (not that he's brilliant at sticking to it!).

By the end episode 2, the two species discuss the state of water pollution, with humanity promising a 50 per cent reduction by 2065. For Salt, that's not good enough, and she refuses to accept that the Homo Aqua should live in that state for one more day.

After Barclay is told to tell Salt that it is humanity's "greatest desire" to clean up the oceans and waterways, she decides to grant it, pulling all of the plastic out of the oceans - and letting it fall down on the streets. When Kate Lethbridge Stewart (Jemma Redgrave) pleads with her to stop, Salt says: "We are cleaning up your mess."

As for how exactly Salt was able to do this? It's unclear, but it could be something to do with the connection (perhaps telepathic) that she and the other Homo Aqua have.

As people start to die from rubbish crashing onto the streets, an emergency issue is ordered - and war has begun.

Speaking exclusively to RadioTimes.com, Colonel Ibrahim actor Alexander Devrient said of that striking visual: "There is no acting required whatsoever. We are already in this world, 100 per cent, and seeing all this plastic, it's so nasty. Physically, you sort of recoil. It just goes to show how much we how much we waste."

Why was Barclay chosen as ambassador?

Barclay was chosen by Salt as ambassador because she sensed a kindness in him as opposed to the other political figures and world leaders that involved in the negotiations. Following the deaths of the Homo Aqua at the beginning of the series, Barclay made the sign of the cross - a sign of respect - over their bodies.

While this isn't mentioned in the series, there's also the possibility that Salt chose Barclay because of his lack of experience.

As we saw in episode 1, he was only part of the UNIT mission due to an admin mistake that listed him as a replacement for a much more senior recruit. Perhaps it works to Homo Aqua's advantage to pick a human with a lack of experience.

Or, perhaps she's telling the truth and she did pick Barclay because of his kindness. Only time will tell!

How do Homo Aqua communicate?

It's established that Homo Aqua have some kind of telepathic communication going on, with Salt being able to send and receive messages almost instantaneously.

It's not yet clear how this is is happening, with UNIT speculating that it could be a "oceanic mycelium" network, meaning that algae threads in the ocean - or the water itself - could connect various living beings to each other, creating some kind of a hive mind.

Another possibility is that the pearls embedded in the necks of the Homo Aqua could somehow be a method of communication.

What will happen next?

With episode 2 ending on quite the cliffhanger, it's clear that humanity is facing crisis on a major scale. Devrient has hinted at what's to come in future episodes, teasing that this could very easily lead to conflict amid the humans.

"[Humanity] is going to try everything," he explained. "And I think that's what's really interesting is, when your backs are against the wall, you see how different players react, and what the points of interest are for each of these players.

"Maybe that works perfectly in unison to be one voice, or, potentially, there is conflict there as well - and what does that conflict look like? It's tense. It's not a nice environment to be in."

He added: "There are still lots of thrills, and lots of twists and turns to come, epic stunts, massive production design. They've really sort of pulled out all the stops for this one, and it looks great."

Kate Stewart actress Redgrave added: "All I can say about the [upcoming] episodes is that the tension doesn't drop and the stakes get higher, and it's a roller coaster. Stick with it, because it gets tenser and more exciting, more thrilling and more dangerous."

As for how fans might feel when the credits roll on the final episode? "I felt really moved and I felt proud of it, tremendously proud of it as a piece of work," Redgrave added.

"I think Dylan Holmes Williams is a remarkable director, and I think that it's a realisation of some fantastic scripts that I couldn't even begin to have imagined when I read them, because Dylan is such a filmic director...I'm proud of it, and I hope that the audiences that come to it really enjoy it."

The War Between the Land and the Sea continues on BBC One and BBC iPlayer on 14th December.

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