Ffolkes (1979) on Netflix

In England, some men who claim to be reporters, board a supply ship and accompany them as they bring supplies to an oil rig and a production platform. But when they get there, they pull guns and take over the ship. They proceed to plant explosives on the rig and the platform. They then call one of the Prime Mnister's people and tells him that they will blow up the rig unless they are paid what they ask. While meeting with the Prime Minister, her people advises her that it would be best if they pay but she doesn't want to give in to extortion. That's when someone suggests they call Lloyd's because they're the ones who will have to pay if the rig is blown up to and see if they have any options. And they do; Rufus Excalibur ffolkes, a man who foresaw how the rig would be taken and devised a plan on how to reclaim it. So one of the Prime Minister's people and an Admiral goes to see him. ffolkes tells him that they will be going to the oil rig and will get on board the supply ship which is part of ffolkes' plan. But when they do the leader doesn't want him there so he sends him back which complicates his plan.