Main characters: Gerry Wade
Eileen Brent = Bundle
A group of young people are enjoying a short stay at Lord Caterham's house.
Oswald Coote is taking care of this house while, the Lord is away. Gerry Wade, a champion sleeper, is going on Oswald Coote's nerves. He sleeps much too long.
Jimmy Thesiger, Bill Eversleigh, Ronald Devereux and some others want to play a practical joke on Gerry. They set up eight loud alarm clocks to ring one after the other, starting from 6:30 a.m. The attempt to wake Gerry up doesn't work. In the morning they find out that Gerry is dead due to an overdose of chloral, which is a kind of soporific. Everyone is shocked to hear the news of Gerry's sudden death. The young people leave Lord Caterham's house as their stay comes to an end.
Lord Caterham returns with his daughter Eileen Brent, whom everybody calls just Bundle. She is a very lively and curious person. When she hears the news of Gerry Wade's death, she wants to see the room in which he was found dead.
What attracts her attention is the fact that seven alarm clocks are arranged in an even row on the mantelshelf. She also finds Gerry's letter to his half-sister, Loraine Wade in which he mentions a "Seven Dials business".
Eileen decides to drive to town. She is driving rather fast, when suddenly a young man coming from the back of the hedge appears right in front of her car. With a risky manoeuvre Eileen manages not to hit the young man. When she looks back, the man is lying on the road without a motion. She runs to him immediately and finds him to be still alive. The young man whispers "Seven Dials.tell.tell.Jimmy Thesiger" and closes his eyes. Eileen puts the casualty into her car and rushes to the local doctor. After a short examination the doctor says that the patient was shot and is dead. The young man's name is Ronald Devereux. Bundle realizes that this person lived in her house when Gerry died. She intends to find out more about the "Seven Dials" and meets Superintendent Battle. Battle is surprised that Eileen is familiar with the "Seven Dials" but isn't much of a help. He suggests Eileen should contact Bill Eversleigh. Bill knew Gerry, Ronny and he also knows Jimmy Thesiger.
Bill tells Eileen where Jimmy lives. When meeting Jimmy, Bundle gets acquainted with Loraine Wade. Bundle tells the two what exactly happened and also about the "Seven Dials".
Jimmy explains that "Seven Dials" is an international criminal organisation. He is convinced that Gerry, who worked for the Foreign Office knew too much about this organisation, that is why he had to die. Also Bill works for the Foreign Office.
Jimmy knows, that Bill's boss, George Lomax is planning a party. It is a meeting of important businessmen, who intend to negotiate regarding a secret formula.
George Lomax received a threat letter. Something is supposed to go wrong during the planned party.
Bundle, Jimmy and Loraine want to start their own investigations. Jimmy thinks it could be too dangerous for Bundle and Loraine. Bundle begins her independent investigations. Somehow she manages to find the Seven Dials Club and hide herself in the room where the meeting should take place. Altogether seven well dressed persons appear at the meeting. All of them wear masks.
The mask is a mere piece of material hanging in front of the features like a curtain in which two slits are pierced for the eyes. In shape it is round and on it is the representation of a clock face.
From the conversation Bundle finds out that there will something happen at Lomax's party. After this discovery Bundle meets Jimmy. They both tell Bill Eversleigh the latest news. They plan to go to the party. Loraine has to stay home as Jimmy doesn't want to put her in jeopardy. Trying to convince Bundle to stay away from the party would be useless.
Superintendent Battle is also at the party. George Lomax invited him for the peoples' security. A lot of dramatic things happen during the party. One tries to steal the secret formula, someone shoots at Jimmy, a Hungarian Countess faints and finally Loraine, who was supposed to stay at home, saves the package with the secret formula. Battle asks some of the people several questions but the facts don't make much sense.
Jimmy is sure that Sir Oswald Coote, who was also at the party is involved. After further research everything speaks against Oswald Coote.
Bill meets Jimmy and informs him that he knows who is responsible for everything.
Soon after that Jimmy calls Bundle and asks her to come together with Loraine to the club where she saw the Seven Dials the other day. Bundle and Loraine drive to the club but it is not yet open, still they manage to enter the club. After a short while Jimmy shows up at the location. Bill is still in the car because Jimmy wanted to check first if everything was in order at the club. When Jimmy finds out that there is no danger he asks Loraine to go to the car to bring Bill along with her. Loraine can't believe her eyes when she sees Bill sitting motionlessly in the car. She alarms Jimmy immediately. Fortunately Bill is alive, so they carry him into the club. Jimmy wants to call for a doctor. In the meantime Bundle hears some noise upstairs, she climbs up the stairs and suddenly someone hits her from the back.
When she wakes up there is an answer to all the questions:
The Seven Dials is an organisation to fight criminality. Superintendent Battle is the leader of this organisation and he explains Bundle all the details:
Jimmy Thesiger has been after the secret formula all the time. Lorraine was his accomplice and could provide him various details as Gerry Wade, her brother, was one of the Seven Dials. Both Gerry and Ronny Devereux had to die since they knew that Jimmy was the criminal they were looking for. When Bill told Jimmy that he knew everything, the latter wanted to eliminate Bill and Bundle.
Finally Bundle gets a proposal to join the Seven Dials and to take responsibility for the Security of the country.