April 22 1848, and now that the party is well and truly over, the diminishing crew prepare to start their long march to salvation.

It’s a tough decision for Crozier (Jared Harris) to abandon the Terror and Erebus, but now that he has kicked the booze, the party’s leader accepts that the only real chance of survival is dragging sleighs of supplies across the barren landscape. There’s an awful moment when the advance party that set off on the 800-mile trip a year ago are found frozen in the ice – they never reached help, and this head start was all for nought.

And if the hard labour of dragging the supplies wasn’t back-breaking and soul-destroying enough, there’s the makings of a mutiny as splinter groups start forming among the ranks. There’s a sense this week of moving forwards as we move in to the final third of the series. I wouldn’t say that there’s much hope – there’s very little of that here – but at least narratively we’re moving closer to the inevitable doom.

As good as the studio sets are, it’s when the crews are out in the real-life bleak landscapes that you really feel the chill and isolation. And when a party of Inuit hunters appear just over a distant ridge, your elation is suddenly tempered with the realisation that this isn’t going to end well.

Verdict: Compellingly dreadful (in the correct sense), this is the very definition of misery TV and is relentless in sharing the next set of tragedies heaped upon our doomed survivors. 7/10

Nick Joy