Another dramatic tonal gear change in this fantastic series this week. And also a change of period, with writers Reece Shearsmith and Steve Pemberton taking centre stage in The Trial of Elizabeth Gedge, set during the witch trials of the 17th Century.

Shearsmith and Pemberton play Warren and Clarke (decide for yourselves if that’s a homage to the late actor), who are called in to oversee a trial in the village of Little Happens. Is Elizabeth Gadge (Ruth Sheen) a sorceress in league with the devil or just a smutty old hag?

This episode is clearly a labour of love for the team. Shearsmith appeared in Ben Wheatley’s mud-soaked movie A Field In England which was set in a similar milieu and I assume he is a fan of  the classic Vincent Price Britflick Witchfinder General, which casts a big shadow over anything that involves witches, familiars, villagers with grime on their cheeks and gratuitous torture.

The drama is all the more hauntingly funny because it is played pretty straight, although David Warner as dimwitted justice Sir Andrew Pike does provide some offbeat humour. Paul Kaye and Jim Howick are on hand with sterling support, mucking in as villagers. As ever, revealing too much would ruin the fun.

Needless to say there is a twist in the tale. But if you are a fan of Inside No. 9, which of course you are, you will know that already.

Inside No. 9 – The Trial of Elizabeth Gadge, Thursday, April 9, BBC2, 10pm