Influenced by her father, a young woman in Ireland wants to fight the English and becomes involved with German spies while an English intelligence officers likes her and follows her.
At night a man in a trench-coat walks on the Rue de la Gare. He hears a shot and runs to a signpost on the Isle of Man showing four miles to Ramsey.
In 1937 at a small pub in western Ireland men are drinking and listening to Danny Quilty tell his story about his role in the Irish rebellion of 1916. Behind a door Bridie Quilty (Deborah Kerr) is listening to his rage against Oliver Cromwell, and she silently mouths the words. Danny says he fought with Michael O’Callaghan, and the British soldiers captured them. He says they sang, and the people in the bar sing “Kelly the Boy from Killane.” Bridie thus came to hate everything British.
In 1944 Bridie comes of age, and at her 21st birthday party she tells her family and friends that she decided long ago she is going to Dublin. Uncle Timothy (Liam Redmond) and others ask her why. She insists she can look after herself. She says they will become as proud of her as they are of her father Danny. She goes upstairs to get ready to go. Maggie says that all the men who have said they fought in the uprising could never have been held in Dublin. She says Danny set out for Dublin, but there are many pubs on the way to Dublin.
Uncle Timothy accompanies Bridie to the train, and she gets on as it is pulling out. In her compartment she observes J. Miller (Raymond Huntley) and assumes he is English. She mentions that the English only think about business. He says they think about other things. She says her aunt told her all about the English classes. She hates all of them and hopes to fight against them. He asks if she is neutral, and she says she is neutral on one side.
The train stops, and Miller carries her bag to a coach for her. She tells the driver to take her to the Redmond Portrait Gallery. One horse pulls the coach there, and she asks him to wait.
Inside she asks to see the Deputy Director Michael O’Callaghan and says she is Danny Quilty’s daughter. A guide shows schoolgirls portraits of the Irish revolutionaries, and one is of O’Callaghan. Michael O’Callaghan (Brefni O’Rorke) asks what she wants and invites her into his office. She says her father talked about him. He asks why she came to see him, and she confides in him that she wants to join the Irish Republican Army. He says they are not at war with Britain, but she wants to carry on the private war going on for seven hundred years. She says Ireland is still partitioned. He thinks they can settle their difference with England on a “friendly basis.” She does not agree and says he has forgotten things. He says she lives in a remote village and that times have changed. He says constitutional means are better. She realizes he will not help her, and he apologizes. She says he has grown old and soft. She asks if he is the same man as he was in 1916. He asks her to think over what he said and says goodbye. He opens the door, and she goes out. She looks again at the portrait of Roger Casement who was executed for treason.
Miller goes into a bookstore and confers with another man while he pretends to look at a book. Miller says he is going to England with an Argentine passport. The man with a moustache asks if he ever met Oscar Price who has vital information they must get. He must help him escape from prison and gives him a guidebook to Wynbridge Vale. Bridie asks for books on Germany and buys one. Miller buys the guidebook and follows Bridie.
Bridie pours white paint on a statue of Cromwell, and a worker tries to clean it off. People gather and discuss the incident. Bridie pushes an old man in a wheelchair, returning to an inn. She tells the soldiers she is not competing with Betty Grable. She helps Granddad (James Harcourt) back to his room.
At the desk David Baynes (Trevor Howard) takes a room, and Miller talks about the weather, asking if he came for fishing. Mrs. Edwards tells Bridie to show David to his room. Miller asks for another drink and reads the register.
Bridie shows David his room, and he says his grandmother is at least half Irish. He asks how far it is to the sea. He asks if she knew anyone who could show him around the town. She says he is quite quick, and he says he has been working with the American army.
Bridie tells the soldier Harry she is ready, and they go out. David comes back to the desk and gets a drink, talking with Mrs. Edwards and Miller. She says Miller is there to buy bulls for cattle breeding. David goes across the street, and Miller watches him.
Harry is chattering about his mechanical work, and Bridie says it is very late. She says goodbye, gives him a quick kiss, and goes inside. Miller knocks and is let in by Mrs. Edward. He apologizes, says goodnight, and goes upstairs.
Miller goes into a room, and Bridie tells him they are taking Pryce to London on Tuesday evening on a train. She got the information from Harry. He asks what she thinks about the man in 16, and Miller says David is an intelligence officer who went to the police station. She asks if he will be in the way and asks if Miller will bump him off. He says no, but he would like her to go out with him and keep him occupied. She is offended and at first wants to refuse.
Bridie and David walk in the country and sit on the grass. He asks her the time, and she says it is half after six. He says he is working on his thesis about Cromwell. She hates Cromwell and tells him how he murdered the Irish. They argue about him, and he suggests they go back. She apologizes for losing her temper. He asks if she put the paint on his statue. He likes her smile and says he would help her.
At night two British intelligence officers talk in their office. Outside a van stops, and Pryce is taken out. An officer signs for the transfer, and two officers escort him inside. In a car Miller is watching. Another van delivers a prisoner to other officers, and he is taken to the intelligence office. The intelligence officer (David Tomlinson) says he is not Pryce, and the man tries to get away; but they grab him.
Outside by the van two officers take Pryce to the car where Miller is waiting. They take off.
David and Bridie are sitting together outside, and he hears the clock strike nine. She says it is not that late. He says he can stay there with her. She says he got her there on false pretenses and says she is going home. She runs off, and he runs after her.
Miller is driving fast and talks with Pryce. They are being followed by the intelligence officers. The first car turns left and goes into a tunnel, but an army truck is blocking the other end. They get out of the car and try to escape on foot. Soldiers go after them, and Pryce is shot. Pryce tells Miller that everything is in a note book on the Isle of Man. Pryce orders Miller to go and shoots at the soldiers. Miller is wounded but escapes.
David and Bridie are walking in the streets, but she does not talk. Back at the inn she goes in her room, frustrating him. She finds Miller sitting, and he says he was shot. He says he must give her orders. He says Pryce is either dead or in custody. He says Pryce was arrested on the Isle of Man, and he hid a book in a courtroom. She is to take his place on a train in the morning and meet a man who will be in the first-class, non-smoking compartment in the northern section. She is to ask for the window to be halfway down, and they are to get off together. He says she is to take his papers and tells a woman that he died for Germany. Finally he asks her to get rid of his body.
Many soldiers are drinking in the inn, and granddad (James Harcourt) asks Mrs. Edwards (Olga Lindo) when Bridie is going to take him out. Bridie says he will have to wait.
Late at night Bridie pushes a wheelchair, and David insists on talking to her. She tells him to leave her alone but promises to see him when she comes back. He agrees to wait in the lounge. She wheels Miller’s body down the street. She is afraid and wonders if she will make it. People come out of a theater, and she walks with the crowd. A man talks to her, and she tells him to go away. A policeman stops them, and the man goes away. She says the man in the chair is asleep, and the policeman helps her cross the street.
At the inn granddad asks what happened to Bridie. David sees that she came back with an empty wheelchair. Bridie comes in, and granddad wants her to take him out. Bridie tells Mrs. Edwards that she took him out a half hour ago. David is listening. Bridie says she is going to bed. Granddad says he has been waiting and has not been out. Bridie persuades Mrs. Edwards that she took him out because the dog is asleep. They say goodnight, and Bridie tells David she can’t talk to him. He says she came back with an empty chair. She says he got out of the chair and walked in. Then she runs into her room. She sees Miller’s hat, and she puts his papers in a purse. She puts the hat up the fireplace. In her nightgown she goes to bed and listens to the rain. She remembers Miller and dumping his body off a cliff. She sits up, and the hat falls down.
In the morning Bridie leaves with a suitcase and gets on a departing train. David has followed her and gets on another train car. He moves past soldiers, but the car’s door is locked. Bridie goes into the first-class, non-smoking compartment in the northern section. She observes four women and three men. A man puts the window half way. She asks for the window to be up and then later asks for it to be halfway down. She waits for someone to say something. At a station two men insist that a little lady get out with them. She walks away with them. A man in a straw hat (Norman Shelley) sees them and gets on the train in that compartment. David joins Bridie and wonders what is the matter. She thinks the old lady is the one she was supposed to meet. She does not know what to do and thinks of going home. She hears David talk about wheeling a body out for burial.
At the next station David gets out, and Bridie tells him to get back on because she is only changing trains. He stays with her, and the man in the straw hat follows her. David orders two coffees. She sees a newspaper headline about a German spy being shot during an attempted escape at Wynbridge. David offers to help her. She says she is going to Manchester.
David and Bridie register at a hotel after trying others. The man in the straw hat is there too. She asks David why he is following her. They go in rooms 22 and 23. She locks her door and reads the news story that says they are “searching for confederates.” She realizes that is her. She undresses and thinks David is a nice Englishman. She figures he may be in love with her. She plans to go to the passport office to get a permit. She notices a news article that there is a ban on travel to Eire (Ireland) because of troop movements. If she can’t go back to Ireland, she will go to the Isle of Man. She tries to sleep. She hears the door open and asks who is there. She gets up and screams. She turns on the light, and David comes in. She says it was nothing. She denies she screamed and closes the door.
In the morning Bridie comes down stairs and asks where she catches the boat for the Isle of Man.
Two men examine the cliff and notice the wheelchair tracks.
In an office intelligence officers have the girl’s description and read that she boarded a boat to the Isle of Man. They call two officers on the island who have been talking to their families on the phone. They are ordered to arrest Bridie and are given her description. The two men discuss how to find her. They see her crossing the road, and one says she could fit the description among many others.
Bridie goes upstairs with a man to the gallery over the courtroom. She sits in the first row and reaches into a crack in the fabric. A man tells her they caught a spy in that seat. She reaches inside the seat cushion and takes out a small booklet. She is told not to move, and a man takes a photo.
Bridie walks by the sea and sits on a bench. She takes out the notebook and reads directions to a French town on the Isle of Man four miles north of Ramsey. She goes to the signpost and sees a fence with a sign saying the War Department does not allow admittance. She wonders what the explanation is and catches a streetcar. She thinks it could be the invasion. She thinks they are planning. If the Germans had that information, they could be ready for them. She thinks how she has English and Irish lives in her hands.
The two officers check the register of the Ocean Bay Hotel, and one asks about single women. They see Bridie again and ask when she arrived. A woman tells her she is Mrs. David Baynes.
Bridie goes into the elevator with the man in the straw hat. He follows her and notes her room number. In her room Bridie lights the fire and puts the notebook in the flames. She hears a knock and answers the door. The two officers come in and ask to see her identity card. She shows him, and one writes down her information while the other lights his cigarette from the fire. David comes in and says he is her husband. The two officers leave. She asks David how he knew. He says the hotel register and asks where she got that false identity card which is a felony. She tells him to go, but he refuses. She cries and says she is miserable. She asks why he came there. He says she led him on and that he is in love with her. She asks if he knows who she is. She says she is a “retired spy.” She says she destroyed everything in the notebook. He asks if she knows the implications. He says he is an army officer and will have to turn her in. A maid comes in to turn down the bed. The maid wants to go to Canada to get married. She goes out. Bridie says she did not do any harm. He asks what would happen if the Germans got hold of her. She says they would not get information from her, but he says they would. He turns around and sees she has gone.
Bridie goes to the dance floor and tells the officer that David is not her husband. He gives her raffle ticket 211 and dances with her. David arrives and searches for her. She tells the officer she must tell him something; it is important. She says she is the woman he is looking for. Just then he sees a friend and feels guilty. The straw-hat man dances with her and asks what happened to Miller. The other officer tells the officer that there is no Mrs. David Baynes. He says they must grab her. A man announces that 211 wins the first prize. The officer says he bought her 211. No one claims the prize.
Outside David finds the 211 ticket by a harbor. He gets on a small boat and goes in the hold. There the straw-hat man is slapping Bridie, demanding that she talk. Three men are trying to get information from her and David.
The boat moves across the sea to the border region between Ireland and Northern Ireland. They take a rowboat to the shore, and sailors see them and alert the police.
A policeman asks a clerk at a train station if he saw four strange men and a woman. The man in the straw hat is holding a gun on the man.
On a stage coach the three spies are taking Bridie and David. On a narrow road they are behind a funeral party. Police stop them and tell them to go on. The spies decide to stay with the procession. Bridie asks David why he followed her, and he says habit. Police stop them and learn it is to bury someone in that country. The man says he has permits for the whole party, and the police let them go. They hear bells, and the man says it is an alarm clock. The police open the casket and find it filled with clocks. The smugglers try to escape. A man is told to take the woman in the last carriage, and he takes her to another carriage with David following and getting on too. They are happy to be free of the spies.
David tells Bridie that he will take her over the border to Northern Ireland and turn her in. She says she has been neutralized and suggests that he ask in the hotel. They go in, and he asks for whiskey and accepts beer. He asks where the police station is and a telephone. He says she is the one they are looking for, and he cannot leave her. She says she will be interned, and he says she can do no harm there. He says he may be fired and imprisoned. She won’t let him do it, and he says she has no choice. The man comes back and says he made the call. She says she is sorry and asks if he could be interned with her. He says no. He asks the price of beer in Eire, and she says they cheated him. Soldiers come in, and he realizes they are in Northern Ireland. He suggests they could slip over the border, but she says no. He urges her to be sensible because police will be there any minute. A man turns on a radio, and they hear the BBC report that D-Day has come; the Allies have begun the invasion. They realize there is no longer any reason for her to be turned in. They leave quickly, see police, and go upstairs to hide. They see two soldiers and a woman go over a fence. She goes out the window and climbs over the fence. Inside the man tells the police she was just there.
Upstairs David sees the straw hat and checkered coat. The spies hold a gun on him. Police hear a shot, and David fights the straw-hat man while another man tries to escape. Police come upstairs and find the door locked. David is fighting the two spies. Police break in and arrest all of them.
Bridie escapes with the two soldiers and the woman.
During peace David and Bridie go into a nice hotel-room at night. He says his hand was trembling as he signed “Mr. and Mrs. Baynes.” He goes to put the car away, and she sees something and gets upset. He comes back and finds her gone. He looks out the window and sees she left. She says she won’t stop there no matter what. He notices the place is called “The Cromwell Arms.”
This World War II spy story has suspense and comic elements as a misguided Irish patriot finds herself involved with German spies while courted by an English intelligence officer. The story shows how young people can be easily conditioned by the beliefs and values of their parents until they go out in the real world and learn from experience for themselves.