The phrase ‘events continue apace’ is not something I thought I would ever write in relation to SS-GB. This tale of a Britain run by the Nazis after losing World War Two has been trundling along slowly for the past three weeks, but finally things have started to happen.

The beginning of the episode was mainly concerned with the aftermath of last week’s explosion at Highgate Cemetery. We saw blood, gore and graphic injuries from the get-go. The established world had had its cage rattled, and all was not well. Even ice-cold SS officer Huth wasn’t himself, reduced to slumping in his chair and drinking away his troubles.

Elsewhere, though, the rule-book of this alternative detective-cum-espionage story was being ripped up still further. There were glimpses of just what has been lacking in the series so far – emotion. The early scenes where plucky sort-of hero Archer packed his son off to the country to keep him safe actually gave his feelings airtime, for once. Getting away from the city, if only for a matter of minutes, gave SS-GB some welcome heart. It also showed Archer tangibly doing something which he hasn’t really done thus far – the right thing.

In fact, if this episode had an aim, it appeared to be to overturn the conventions of the previous three instalments. Blood, guts, pain, grief and fighting back were all on the agenda during this hour, all the things which have thus far been suppressed.

But this episode wasn’t done yet. There was more. Harry Woods and Sylvia were detained along with many others as part of martial law following the explosion. The SS and the army kept on with their battle for supremacy, whilst Archer continued plotting to get the King out of the Tower of London and hiding the plans for an atomic bomb whilst seeming to his German colleagues to be entirely straight-laced. The gravelly-voiced, stony-faced copper is finally proving his worth, and about time.

This penultimate episode of five was a marked improvement on the last, helped no end by the slow-burn elements of the series so far starting to come to fruition. This hour left proceedings in a very tense state indeed. Sylvia had escaped and was lying low at Archer’s place. Archer and Woods were planning how to liberate the King and get him across to America. And Barbara, the lover to whom Archer had gifted the atomic plans, had been arrested.

The end is in sight. Everything is set for a big, no doubt twisty finale on Sunday. The time for heroes has come, and to this adaptation’s credit, it’s still of interest whether or not they triumph. Let’s hope the end has been worth the wait.

SS-GB concludes on Sunday at 9pm on BBC One.