The Tudor epic about a tyrant king and his vengeful, backstabbing entourage is back for its final instalment – and it’s more brutal than ever. We go on set to talk to the Mirror and the Light team about death, dictatorship … and ostriches

It is a treacherous landscape, the set of Wolf Hall, which sits under grey clouds beside Wells Cathedral. Outside in the field, production vans spin their wheels and horses kick up mud. Inside, the Bishop’s Palace is mined with cables, scaffold and lighting rigs. Visitors are advised to tread carefully. Danger lurks at every turn. “You watch yourself there,” cautions Timothy Spall. “You won’t lose your head, but you might lose your balance.”

For three months, Wolf Hall’s cast and crew have shuttled between England’s heritage sites. They’ve shot at Hampton Court (where the planes were a nuisance) and Haddon Hall, Lacock Abbey and Montacute House. Now at last they’re in the final straight. Cooling his heels in his trailer with a flask of hot tea, Spall explains that he has only one scene left to film – performing opposite lead player Mark Rylance inside the columned hall. Spall has been acting for decades. He knows his work back to front. “But you know what?” he says. “I still have the same sick feeling in my stomach. Every time I step out it’s as though it’s the first job again.”