The star of the harrowing historical thriller reveals five secrets from the set

1 I play Francis Crozier, captain of the Terror, a Navy warship that was part of Captain Sir John Franklin’s real-life lost expedition to the Arctic from 1845-48. Much of the action takes place after the Terror and sister ship the Erebus get trapped in ice. Large sections of the ship were re-created but some ceilings were made higher – so we didn’t bump our heads!

2 The plan was to refrigerate the sets so our breath could be seen. But when we filmed in Budapest, Hungary – in the middle of winter – the studio doors were left open and the temperature fell to -15. We also filmed on an island off Croatia called Pag, with winds up to 200mph. We watched our sets blow away and had to wait.

3 There’s an ailing creature lurking on the ice – getting more prominent during the series – called Tuunbaq. It was a remotecontrolled bear-like monster that could climb the Terror’s mast. Three models were used to reveal its stages of deterioration.

4 I went to the National Maritime Museum in Greenwich to read the letters the real Crozier [left] sent back to England before he disappeared. They tell a sad tale of a man rejected in love by Sir John Franklin’s niece, Sophia Cracroft, and who was devoting himself to life at sea. Some of the melancholy I inject into Crozier stems from those letters.

5 Crozier has scenes in Inuit – the native tongue of people of the Arctic region. I wanted time to learn it but on day three I had a huge scene in Inuit, written just the night before. I had to have an earpiece to feed me the lines.

Jared (right) with Tobias Menzies as Capt James Fitzjames