Please answer the following question: Build a movie plot around this: Why do they feed Helena a dead German's leg? To turn her into her demon form.
A:
On 5 June 1944, commandos are sent to the Channel Islands on sabotage and distraction raids, to draw Hitler's attention away from Normandy. That night, two New Zealand soldiers, Captain Ben Grogan (Craig Hall) and Sergeant Joe Tane (Karlos Drinkwater), paddle in their Klepper canoe to Forau Island, landing on a beach covered in anti-personnel mines and tank traps. When they leave the beach and head inland, they begin to hear distant screaming and gunfire. They approach a German fortification and hear what they think is a man being tortured. They climb down into a large gun pit and place explosives on a large artillery gun but are disturbed when a German soldier (Luke Hawker) runs out of a tunnel pleading for help. Grogan stabs the soldier in the back of the neck and kills him. They hear a woman screaming, and Grogan decides to investigate while Tane remains outside. However, when Tane hears a gunshot he also enters the bunker to investigate. While looking for Grogan, he discovers a book of black magic and, distracted by its contents, is killed by an unseen assailant. Grogan, unharmed, later discovers Tane's body but is immediately knocked unconscious by the Nazi.Grogan wakes and is briefly tortured by a Nazi, Colonel Meyer (Matthew Sunderland), who wants to know his mission. During the interrogation, Grogan hears a woman screaming from another room. He eventually escapes and chases Meyer into the tunnels, shooting and injuring him. When he follows the sound of the woman's screams up to a room covered in occult symbols, he discovers that the woman is his dead wife, Helena (Gina Varela). Meyer enters the room and shoots Grogan in the leg, then shoots Helena in the head, apparently killing her. Grogan attacks Meyer, who explains the woman is a demon, summoned up from a book of black magic found on the island. Meyer proves this by offering her the leg of a dead German to eat; she changes into her true demon form as she eats the leg.After Grogan removes a bullet from his abdomen, Meyer passes out. Grogan...