Plot

1943: Operation Mincemeat, key to the allied victory in WW2, is at stake. It all lies in a captured Spanish spy in Nazi-occupied France, who turns out to be an important figure in the Ministry's past, and its future.

Luchon, France, 1943. The then young Lola Mendieta, an allied spy during World War II, and the English officer William Martin are at a tavern planning of crossing the border to get to Spain. The meeting is interrupted when a German patrol appears at the tavern looking for them. The bartender, an accomplice of both, sacrifices his life so the young woman and the officer can leave the bar alive. Unfortunately the only survivor is the Englishman, after dodging several Nazis. The spy ends up being captured by the Germans.

Lola, in the present, accompanied by Lucia, is very sick at the hospital waiting for the visit of Salvador, who she called to asks him to save her. Offering the complete Book of Doors in return. At the ministry, Salvador, Irene and Ernesto talk at Salvador's office about the proposal he received from Lola and the murder of the Russian. Whom are interrupted by the intrusion of Angustias. She informs the three present at the office about the kidnapping of Lola by the Germans in 1943. Pacino and Amelia talk in the ministry's cafeteria about the latest events. This way she tricks him into admitting he let Marta escape during the last mission. The third component of the patrol is still at home with Elena, having a brief morning chat until the searcher pokes on his nightstand and gets up and leaves the conversation halfway.

The entire patrol, accompanied by Salvador, Ernesto and Irene, comment on the situation regarding Lola, whom they must save as soon as possible as she is being taken to a concentration camp to torture her until she confesses the passwords to the famous "Operation Mincemeat". Amelia, Pacino and Alonso embark on the mission, accompanied by Ernesto, to a small French town where they try to intercept the truck that is taking Lola to the camp. But the risky plan ends up failing. One of the agents of the ministry, pretending to be German, does not speak the language and ends up being discovered. Lola has the opportunity to escape between shots, but Ernesto's leg is wounded. Although she has the chance to save her own life, she with him trying to help him. As a result the are captured by the German army. Back in the ministry, in the present, embarrassed by what happened, the patrol reports on what happened in 1943 to Salvador and Irene, who, faced with the critical situation they are living, entrust the others with the difficult task of helping William Martin to make "Operation Mincemeat" succeed.

In 1943, Ernesto and Lola arrive at the Gurs Concentration Camp, where they are locked inside a room. Meanwhile, Pacino, Amelia and Alonso arrive in Huelva overcoming some other obstacle during their trip. Salvador, in 2017, tells Angustias the story of Lola's life while Ernesto and Lola talk about the same subject in the 1943-time. Right until they are interrupted by the Germans, who grab Lola to take her away. When she gets back, after being interrogated, she appears to be badly injured and physically weaker.

Salvador, in the present, continues feeling bad and talking about it in his office with Angustias. The talk about life as a spy and how complicated the situation is. He finishes confessing that exactly as written, Lola Mendieta did not participate in the Operation Mincemeat. Not like she's doing now and that nothing is happening as it should be.

The patrol watching William Martin runs the streets of Huelva looking for him. They find him in a bar where they find him singing to the rhythm of a flamenco guitar. Conversing they learn London has stopped the operation, but after repeating the importance of the matter, they convince Martin to try to restart it. The response of London remains negative, the Operation Mincemeat remains suspended.

In the concentration camp it's Ernesto's turn to be interrogated. He ends up being beaten the same way Lola was.

Trying to reactivate the mission on their own, the three protagonists along with William Martin, prepare to make everything go as it should go. They visit a friend of Williams, who offers to help without any hesitation.

In Gurs, Ernesto and Lola, receive the visit of Father Azcárate in the middle of the night. He brings a message from Salvador to the agent. In case Lola ends up talking, he'll have to kill her. Meanwhile in the ministry Irene deals with the murder of the Russian who happens to be an agent of the ministry of 1958, disappeared on a mission in the thirteenth century. Salvador receives a call from the priest who has visited Lola and Ernesto, reporting the situation of his colleague in the concentration camp.

Amelia, Pacino and Alonso, along with William and Naylor, plan a way to go forward with the operation on their own. Gathering everything necessary to make it work. Meanwhile, they try to have fun and after taking a few photos, necessary for the plan, both the family of Mr. Naylor and the rest of the group involved in the mission play a football game on the beach. Amelia and Pacino talk a few seconds about the situation in private. But Pacino manages to encourage the her to have a good time with the rest of them.

The young spy and the kidnapped agent comment, while still in the room, how complicated everything has become. Lola, taken by the cold atmosphere in the room, collapses. Ernesto tries to comfort her and takes her in his arms to give her some warmth talking to her, realizing he will have to do what he doesn't want to do.

While the patrol and William sleep in Huelva, in the London offices the English, after receiving news, decide to restart Operation Mincemeat. Despite not receiving an answer from the officials in Spain due to a poorly placed cable in Martin's machine. Due to that same reason, an English submarine travels towards Punta Humbría, Huelva. William and the patrol wake up that morning continuing the mission they had set in motion. Martin suggests some ideas to make the story more credible and chooses to write love letters from the alleged dead official to his wife and vice versa. Amelia is in charge of writing those of the fictitious wife. Meanwhile, Pacino and Alonso take a walk on the beach talking about how difficult it is for Alonso to impregnate Elena. Pacino explains what the pill is to an astonished Alonso. Pacino talks about on how familiar the name of William Martin sounds to him, although he does not know why. That night, with the help of Naylor, William and the patrol go to the morgue in search of a corpse that they can throw in the sea. They end up not finding do not finish finding the body they need to carry out the mission. William can't sleep, so he gets out of bed and starts writing a farewell letter. He put's on his officer's outfit and leaves the house, with the attentive eyes of Alonso on him, who leaves behind him, a few steps behind.

Back in Gurs, Ernesto tries to fulfill the order of Salvador. But he unfortunately he's unable to do it.

Martin arrives at the beach, but is intercepted by Alonso who tries to stop him. He ends up paying him his respects, taking into account the decision he made and right after that he walks into the sea. At William's house, the patrol shares with Naylor the news, but London has contacted him to inform him Operation Mincemeat has been launched again, which causes anger to Amelia, Pacino and Alonso, who notice the failure of the cable. At that moment a message arrives that informs the sinking of the submarine. They realize the death of William has not been for nothing and that the mission still stands. Everything has to be done and has to happen as it actually happened in the past. This is why the patrol listens to the indications of Pacino who knows the story by heart. With William already in the morgue, the forensics give their approval. Williams is being buried in his home town. The mission is a big success.

Lola and Ernesto are being taken out of the room to be executed. They are being placed against the wall, they cover their eyes. Salvador and his agents appear at the last moment to save them.

Salvador finds out that the present Lola has died due to illness when he returns to visit the hospital. This one leaves him a farewell letter.

Pacino finally discovers why the name of William Martin sounds so familiar. He turns out to be the man who appears in the novel and in the homonymous film about the history of Operation Mincemeat.