Miranda Frost

Miranda Frost is the hidden secondary antagonist in the James Bond film Die Another Day. Frost is a double agent working for MI6; however, her true allegiance lies with Gustav Graves, the main villain of the film.

She is portrayed by Rosamund Pike who portrayed Amy Elliot-Dunne in Gone Girl.

Background
Miranda Frost is a Harvard-educated, gold medal-winning Olympic fencer (trained by Verity) posing as Graves' publicist and fencing partner. She won gold at the 2000 Sydney Olympics by default, after Graves organized the real gold medalist's death by drug overdose.

While Bond is sent to kill North Korean Colonel Tan-Sun Moon, Frost secretly sends Bond's true identity to Zao, Moon's right hand. This leads to Bond's imprisonment at a North Korean torture camp, where he is brutally interrogated for 14 months before being exchanged for Zao.

Double Agent and betrayal
She is sent by M to work alongside Bond, but does not approve of Bond's methods. When caught by Mr. Kil and his minions, Miranda helps Bond keep incognito by kissing him. They later go to Frost's room and have sex. Unbeknownst to this, Frost empties the magazine of Bond's gun after this.

When James awakens and goes after Graves, Miranda pleads for him not to go, but he insists. Later when Bond faces Graves at gunpoint, Miranda arrives as well, also aiming her gun at Graves. However, Graves asks Bond whether he already found out who betrayed him in North Korea, prompting Frost to aim her gun at Bond, revealing that she was the one who betrayed Bond. Bond escapes with the ring that Q gave him by breaking the glass floor beneath them, and Frost and Bond fall into the jungle environment part of the Ice Palace. Frost shoots at Bond while he runs off, but misses and Bond escapes.

Demise
When Jinx and Bond enter Grave's plane to kill him, Jinx goes to the cockpit while Bond goes after Graves. However, Jinx is caught by Frost, who fights Jinx, and she and Jinx have a climactic fight aboard the descending plane. Frost narrowly sliced Jinx in the stomach but Jinx manages to impale a dagger in the chest of Frost, thereby killing her.