
7.5
When a fearsome and ancient species emerges from the ocean, dramatically revealing themselves to humanity, an international crisis is triggered. With the entire population at risk, UNIT step into action as the land and sea wage war.
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1Episode 1Homo Aqua
44 min
Barclay's ordinary life becomes a world of terror when an ancient species rises from the sea. As UNIT fights for control, the summit on the Thames reveals terrifying secrets.
2Episode 2Plastic Apocalypse
48 min
Barclay becomes humanity's ambassador when the mysterious Salt emerges from the Tank. But his family's life is torn apart when Salt wreaks revenge upon all mankind.
3Episode 3The Deep
45 min
Barclay makes a terrifying descent into the world of Homo Aqua. Back on the land, Kate stands alone as Downing Street conspires with the army to change the course of the war.
4Episode 4The Witch of the Waterfall
46 min
Barclay and Salt go on the run in a war-torn London as UNIT reels from disaster. But when Tide threatens the land and Gunsberg advances his plans, the Severance schemes demand blood.
5Episode 5The End of the War
54 min
Barclay stands alone, Salt is lost, UNIT is powerless, and the oceans rise as the war reaches its climax. While traitors conspire, can Barclay find Salt before it's too late?

Russell Tovey
Barclay Pierre-Dupont

Gugu Mbatha-Raw
Salt

Jemma Redgrave
Kate Lethbridge-Stewart

Ruth Madeley
Shirley Bingham
7.3