'I think we do a public service even in our most crass, blasphemic acts,' explains spokesperson and co-founder of The Satanic Temple, Lucien Greaves – a pseudonym as his real identity is a secret. Recently recognised as a church by the United Federal Government, this is the first time in history a satanic organisation has ever received this acknowledgment. Founded in 2013 along with Malcolm Jarry, who appears in Penny Lane's documentary, Hail Satan?, blacked out, the church is standing up for religious pluralism. Their mission statement is made up of seven fundamental tenets, one of which is to, 'strive to act with compassion and empathy towards all creatures in accordance with reason.'

In real life Greaves comes across as extremely smart, his responses are gathered and his passion speaks volumes. He rarely pauses as he elaborates on the recent press release the church sent out claiming exemption from the Supreme Court's ruling to uphold an Indiana law requiring the burial of foetal remains after abortions, something which Mike Pence supports.

'From where we stand the non-viable foetal tissue is within the rights of the woman to contextualise as she sees fit. This has always been a religious question and it's not one for the state to impose upon the woman,' says Greaves. 'This could be a case we could see go all the way to the supreme court. Now that we're in the game it's a whole different story. As far as the abortion claims are concerned this one is particularly strong for us because it is a ceremonial requirement. It would be hard for them to rule against us without seriously redefining what it means to be a US citizen. That said, there's no guarantee that we will win and there's no guarantee that they won't completely redefine what it means to be a citizen. That's really scary to find ourselves on the precipice of a new dark age.'

The decision to allow Penny Lane behind the scenes access was not an easy one, 'I think I'm a very difficult subject because there is a lot I wouldn't do or allow. It wasn't until I saw her previous film Nuts! and saw her do a Q&A related to that. She was talking about this ongoing fight she was having with the anti-vaccination movement and her scepticism of pseudo-science and superstition in general, and also the fact that she had done a lot of groundwork, that I thought she may end up being a good person to work with. I think that's vindicated now but it's very stressful having a couple of years of filming going on and having no idea what narrative is being constructed from that kind of footage. No matter how much you trust somebody you don't know ultimately what's going to be made of your life's work.'

Encouragingly membership has been steadily increasing in the face of political turmoil, 'Sometimes it's hard to know what the factors are involved in that. After Trump was elected our membership skyrocketed and that was the first real skyrocketing of membership. The documentary coming out has certainly contributed and now again we're seeing people very interested in The Satanic Temple because of the restrictions being passed against abortion and people realising that this fight against theocratic nationalism is very real.'

Screening as part of the Sundance Film Festival 2019: London. Selected release from Fri 23 Aug.