Sybil North is engaged to the secret agent Tom Ware. She is shown into his study by the butler. When the butler leaves Tom and Sybil embrace, but are disturbed by the butler, who delivers an urgent message stating that the chief needs to see Tom immediately at the Foreign Office.

Sybil and Tom leave for the Office. As Tom kisses Sybil goodbye on the steps of the Foreign Office, Dr Brian Pellie and his lady friend see them. They decide to wait for Tom and follow him. Inside the Foreign Office, Tom is given a secret despatch, which he must deliver to Russia. He returns home, followed by the spies. Once in his study, Tom asks his butler to pack for him and telephones Sybil, asking her to come and see him. While Tom is out of the room, the spies enter and hide behind a screen. The butler enters carrying his master's luggage and is caught by the spies, gagged and placed behind the screen. Tom enters his study and sits at his desk. The spies emerge and hold a gun to his head; the woman looks for the despatch.

Meanwhile, Sybil arrives and knocks at the door. Getting no reply, she enters via the veranda. The woman spy finds the despatch but a struggle between all three ensues. Sybil enters the room as the female spy rushes off; meanwhile Tom and Pellie struggle. Sybil gives chase and catches the female spy but just as she retrieves the despatch, Pellie, who has escaped from Tom, arrives, seizes the despatch and, together with his accomplice, runs off. Tom soon arrives and he and Sybil give chase.

Pellie and his accomplice board a tram and make off. Tom and Sybil, now joined by policemen, give chase in another tram. Pellie and his accomplice leave the tram and make for their house, full of other spies. They make ready to defend the house and the despatch. Tom and company arrive and are driven back by gunfire from the house. While the army and police return fire from behind a cart, Tom makes his way onto the roof using a ladder. Inside the house all the spies, save Pellie, are dead. He escapes onto the roof to be met by Tom who shoots his hand, they subsequently struggle on the roof as policemen arrive to help.

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