Rent Cold Skin (2017)

At the dawn of the First World War a young man named Friend (David Oakes) arrives at a desolate Antarctic Circle island to take the post of Weather Official observer. But on shore he finds no trace of the man whom he has been sent to replace, just a deranged castaway, Gruner (Ray Stevenson), who has witnessed a horror he refuses to name...Little does Friend know that an unknown race of amphibious humanoids will emerge from the seas every night to besiege him and Gruner in an unstoppable attack to their safety. Will the two men be able to defeat the creatures from Atlantis or will they discover something in themselves that will challenge their view of the world and their unknown assailants?