D’Artagnan (Douglas Fairbanks) travels to Paris to fulfill his ambition to become one of the King’s Musketeers while Cardinal Richelieu (Nigel De Brulier) plots to rule the court of King Louis XIII by involving a scandal with the Queen (Mary MacLaren).
The Cardinal sends his henchman, Rochefort, with a forged letter from the Queen to Buckingham who has feelings for her. D’Artagnan encounters the henchman in Meung who makes fun of his horse.
When D’Artagnan gets to Paris he trades in his horse for a fine new hat and meets Constance (Marguerite De La Mott), the Queen’s seamstress.
In England Buckingham receives the forged letter.
D’Artagnan calls on the Captain of the Musketeers who is scolding Athos (Leon Bary), Porthos (George Siegmann), and Aramis (Eugene Pallette) for fighting with the Cardinal’s guards. He points out to D’Artagnan that they are the three best swordsmen in Paris. D’Artagnan tells the Captain that he’s dreamed of becoming a Musketeer. The Captain tells him “Impossible! Serve your apprenticeship with the cadets for two years – and – we shall see.” D’Artagnan sees Rochefort out the window and runs out of the room running into Athos. Athos tells him he can meet him behind the Luxembourg at one o’clock. He then runs into Porthos and tells him he can meet him at the Luxembourg. D’Artagnan runs out into the street but the henchman is gone. He then encounters Aramis who he tells to meet him behind the Luxembourg at one o’clock.
Behind the Luxembourg at one o’clock the Three Musketeers are waiting for D’Artagnan. When he shows up, so do the Cardinal’s guards. Let the sword fighting begin! (Douglas Fairbanks did a lot of his own stunts and the one handed sword grab in this scene is one of his best!) The fighting goes from the street to inside a local shop. “Thus D’Artagnan, in two days, became the talk of Paris and won for himself the loyal comradeship that was to last throughout his life.”
Richelieu complains that the King’s Musketeers have assaulted his guards. The King tells the Cardinal that these men shall be dealt with properly. After the Cardinal leaves the room the King smiles and tells the Captain of the Musketeers: “I commend you to fetch these four devils who have maltreated seven of the Cardinal’s best men.” The King seems pleased his best Musketeers and D’Artagnan have taken on the Cardinal’s guards.
That evening Constance is getting ready to make a mysterious appointment when the Cardinal’s guards barge in and demand: “Certain messages have been confided in you. Tell me what they are and to whom they are to be delivered.” She refuses to tell. D’Artagnan is lodging upstairs and is awakened. He goes downstairs and fights with all the Cardinal’s guards by himself. Constance faints and he carries her out a window and up on a roof. When Constance is conscience again she tells D’Artagnan: “I dare not delay. Midnight is striking and it is the hour I am expected.” D’Artagnan thinks she is meeting a man. She leaves for her secret meeting. D’Artagnan follows her and sees her with a man who turns out to be Buckingham. They both escort him to the palace to meet the Queen.
The Queen meets with Buckingham and tells him: “Milord, you have been told it was not I who wrote to you – yet you rashly insist on this interview.” He replies: “What does it matter? Nothing matters but that I see you again.” She tells him that he risks her honor by seeing her and he also risks his life. She tells him he must go and never return. He asks her: “Then something for remembrance – something that you have worn – a ring – a chain – a brooch – that I may wear it always.” She gives him the one of a kind diamond buckle brooch the King has given her. He kisses her hand and leaves. Just then she sees the Cardinal getting up from a chair in the room. He has witnessed everything. He uses this indiscretion to his advantage. The Cardinal plans to expose the Queen’s secret at the court ball.
The Cardinal sends Rochefort to deliver a letter to Milady de Winter in England.
The King pays the Queen a visit to remind her of the court ball. He asks that she do him the honor in wearing the diamond buckle brooch he gave her. The Queen sees the shadow of the Cardinal in the doorway. She knows he has set her up.
Constance goes to D’Artagnan and pleads with him to go to England to retrieve the brooch from Buckingham to save the Queen. D’Artagnan enlists the help of his Musketeer friends. In the meantime, her father Bonacieux overhears Constance and sells the information to the Cardinal.
The Musketeers tell the Captain who advises: “On perilous expeditions of this kind you must pay toll. Four must start if one is to arrive.”
The Cardinal makes sure the road and beyond is unsafe. The Cardinal’s guards stop D’Artangan before he can leave town. D’Artangan goes to see the Cardinal but it’s a trap. While speaking with the Cardinal, D’Artangan sees a pistol sticking out from a curtain. He gets away by sliding down a banister of stairs with the Cardinal’s guards in hot pursuit behind him. He escapes and meets up with the Musketeers. Thus four men ride off in the service of their Queen.
At the first toll the four men are ambushed by a man waiting with a pistol. Aramis jumps off his horse and wrestles with the man and the others ride on. At the second toll they come to a bridge that has been blown up. Pathos pays the toll by holding up the broken bridge so the others can pass. At an inn in Calias Athos pay the toll. At the port of Calais where D’Artagnan plans to sail there is a notice that the port is closed.
In England Milady de Winter has received the letter from the Cardinal. It says to retrieve the brooch in Buckingham’s possession and bring it to him.
At night D’Artagnan is able to get on a boat to sail for England.
Milady de Winter is able to steal the brooch from Buckingham at a party. D’Artagnan arrives at the party as Milady de Winter is leaving. He gives a letter to Buckingham who notices the brooch is gone. D’Artagnan realizes Milady de Winter has the brooch and is heading for the harbor. D’Artagnan is able to make it to the boat and stow away. The next morning he is able to get the brooch by fighting Milady de Winter for it. He bites her hand and leaves a mark. He jumps off the boat and swims to shore.
In the grand ballroom of the palace the guests have arrived and the Queen is late. When she does appear she is not wearing the diamond buckle. The King sends her back to her room to get the still missing brooch.
D’Artagnan sneaks in the palace and comes face to face with Rochefort. A sword fight starts carrying them up a flight of stairs. He finally makes it to the Queen’s room and there is Milady de Winter by the Queen’s side. D’Artagnan hides behind a curtain while de Winter goes to it and pretends to be the Queen. She reaches out her hand and he sees the bite mark. He takes the brooch out of the box and hands it to Milady de Winter. After everyone has left the room D’Artagnan gives the brooch to the Queen.
The Queen goes back to the ball proudly wearing the brooch. The Cardinal seeing the Queen has a horrified look on his face. He knows he has failed to take over the kingdom.
D’Artagnan is brought before the Cardinal by his guards. The Cardinal asks D’Artagnan: “If you were about to die, what would you do?” D’Artagnan replies: “Your Eminence, I’d still write the history of France.” The Cardinal says: “Then set down in your book, Monsieur D’Artagnan that Richelieu was a generous foe.” The Cardinal holds back a curtain and the three Musketeers appear. The Cardinal offers D’Artagnan a position as Lieutenant in his guards. He replies: “Your Eminence, my dreams, my hopes, my ambitions are all with the Musketeers. The Captain of the Musketeers shows up and gives D’Artagnan a commission with the Musketeers. He is then presented to the King as a new Musketeer. All for one and one for all!