Miles Machree (J. Warren Kerrigan) meets Irish-American Sheila Lynch (Fritzi Brunette) when she travels through Ireland with her father (James O. Barrows). Soon after the Lynch's return to the States, Miles follows, and through his uncle's connections, gets a job on the New York City police force.
Returning to his father's cattle ranch after the excitement of serving in combat overseas, Bud McGraw becomes restless, and his father decides to send him to an old friend who commands the Border Police in Texas. On the way he meets Peggy Hughes, accompanying her Uncle Graham, a customs inspector, and he retrieves her hat from the rails of a train. At the headquarters, numerous scrapes and fights win him the admiration of, and friendship with, the men. Lazaro, a Secret Service agent, invites Mrs. Graham and Peggy, who are staying at the border station, for an automobile ride, and they are captured by bandits and held for ransom. Bud and his pals deliver the ransom and discover that Lazaro is the bandit chief. Lazaro refuses to release Peggy, but a jealous rival, Nita de Garma, causes his downfall and shoots him as the Border Police arrive to rescue the party.
After his defeat at the hands of "Spider" Flynn, the welterweight champion of Europe, boxer Jimmie Dolan and his trainer, Thomas Jefferson Jones, leave for a principality near Paris. Having lost all their money on the fight, Jimmie accepts Count Conrad's offer to impersonate Prince Frederick in return for a large sum of money.
Lillie's parents are caretakers of the property adjoining Mr. Montgomery's estate. He is a wealthy bachelor. Lillie's pleasures consist in shooting, boating and gathering flowers, while roaming through Mr. Montgomery's woods and gardens. Cobbs, the grouchy gardener, has orders to keep all trespassers off the grounds and in vain to keep the troublesome Lillie away. Jack, the owner's nephew, arrives on a visit, and starts out to frighten away the trespasser, but instead falls in love with Lillie and she introduces him to her parents. A pleasing romance follows and the young people get a bead of fun out of fooling the old gardener and Mr. Montgomery, but Jack always reports that the little trespasser cannot be found.
Fatima decides she needs to reduce her weight. Inspired by the example of famous actress and beauty icon Lillian Russell, she attempts to "roll it off" through various weight-loss methods.
In a bicycle race, Lee is continually stopping to help the girls, and when overtaken by the other riders, he leaps upon his trick bike and passes ahead of them.
When Mrs. Harrison arrives in Harborsport for her vacation, she announces her plan to marry Gladsome, her daughter, to Vincent Bradshaw, the son of her financial advisor James Bradshaw. To keep Gladsome from socializing with the local fishermen, James drives them from his property, but they organize under her and force their way back. Arrested for rabble-rousing, Gladsome is bailed out of jail by James and later meets "Alphabet" Carter, a vacationing financial wizard, for whom she has an immediate attraction.
When an aviator dies performing in a traveling circus, the circus closes and sideshow con men "Sky-High" Billy Wardell and "Domino" Dominick are arrested for giving out fake watches to wheel of fortune winners. After Domino springs the jail's lock, they jump a freight train and arrive in the next town, where Billy falls in love when Jane Higgenbotham allows them to breakfast on her freshly baked pies.
Tommy Buckman, the ne'er-do-well son of dime store magnate John Buckman, is given one last chance to succeed by surveying a possible location in New England for the opening of another store in his father's chain. Arriving in the town of Winton, Tommy lands in jail and, disowned by his father, is bailed out by Nina Potter, whose father owns the only dime store in town.
A villain attempts to win the love of a pretty fisher girl, who is in love with a village youth. The villain finally kidnaps the girl and carries her out to a rock at low tide, where he ties her. He stands on the shore hoping that the rising water will force her to promise to marry him. The water rises higher and higher, tremendous waves dashing over the girl, and when it seems impossible for her to live another minute her sweetheart arrives with a crowd of the village people and rescues her.
Hubby is out of work, and wifey is working as a stenographer, posing as a single woman, in an employment agency. The boss is in love with the pretty typist. He tells her he wants a man right away, and she telephones her husband to come down. He gets the job, which is that of porter. While hubby sweeps the floors and cleans the cuspidors, the boss is holding wifey's hand in the private office. Another suitor, who, also, does not know the stenographer is married, tries to see her and is kicked out by the boss. He tells his troubles to the porter, and then rushes off to tell the boss's wife, for revenge. Hubby listens at the door and is caught by the boss, who tips him to stop spying. The boss's wife, a two-hundred-pounder, arrives just as hubby has gotten up his courage to heat up the boss, and a lively scrimmage ensues.
Brown is troubled with an over-abundance of affection, and his wife and mother-in-law convince him of their displeasure in many ways. Brown has a friend who has never met Brown's folks, and becomes acquainted with Mrs. Brown while she is with her mother. He invites them for an automobile ride and manages to start up the automobile as soon as Mrs. Brown has seated herself, leaving her mother behind. That worthy lady, however, runs after the machine and refuses to get lost. The friend has sent word to Brown to meet him at a restaurant, and Brown has a lot of nice champagne iced and awaits his guests. He is thunderstruck when his wife walks in, soon followed by his mother-in-law, who sit down to enjoy his hospitality.
Mabel, her father and Mr. Tra La La, a suitor, much to her disgust, for her hand, take a trip on the coast steamer, "Harvard." Mr. Short, his rival, follows them. He, with the connivance of the ship's captain, gives Mr. Tra La La a most strenuous and ludicrous trip.
Advantage was taken of the fact that a floral parade was being held at Pasadena, Cal. in which the Keystone car was entered and won second prize, to produce a comedy film around the incident. Fred Mace and Mabel Normand are invited to take part in the parade, and Mack Sennett plans to keep her away and take her place Accordingly Mabel is locked up in her dressing room. But she escapes after considerable difficulty. She rushes to the line of march and makes frantic and amusing efforts to catch the Keystone automobile while the two sleuths attempt to dodge her. Mabel gets into difficulties with the police who are endeavoring to maintain order, and is championed by Ford Sterling, who is among the spectators.
Champion college swimmer and summer lifeguard Ken Holmes saves Joan Stanton from drowning. They are sweethearts until a misunderstanding causes Joan to cast off Ken for his chief competitor, Herb Darrow. Joan promises Herb she will wear his fraternity pin if he wins the big swimming race at the hotel the next day. Despondent over his loss, Ken decides not to enter the race; later, he reconsiders when he learns that Joan is to wear Herb's pin if Herb wins. Ken wins the race and resolves his misunderstanding with Joan.
Two young women transform from an innocent girls into a jazz mad flappers.
Emphatically opposed to Jack Moss, old Mr. McGillicuddy puts the ban on his marriage to his daughter Dolly. The old gentleman is adamant to the appeals of the young lovers and interposes his interference on every occasion, when they get together. McGillicuddy is seized with an attack of the gout, which handicaps him, and it is then Jack arranges with Dolly to elope.
Sir Brian, an irascible old gentleman, who suffers from gout, receives a note saying his son Gerald is very ill at college, and asking him to come to Dublin. He is too ill to go so he gets his friend, Captain Jenks, to go instead of him. Jenks finds Gerald being nursed by a pretty girl and soon discovers that Gerald is in love with her.
Father wants Mabel to marry a little, wealthy shrimp. She is in love with Charlie, a big, strapping fellow. Mabel is locked up in the house, but her lover sets the house on fire, and In the confusion runs to the minister's house with her. Father and his choice pursue, but Mabel and her lover hide in the chimney. Father sticks around with a big gun, and Mabel and her lover make up as negroes and are married, father being persuaded to act as best man.
The night of the grand reception and dance finds Belle Oakley in high glee as she leaves for the reception. She arrives at the reception and discovers that she is without her dancing shoes. She announces her loss and immediately all the young men volunteer to go in search of them. Harry Brown, who was not as quick as the others, is left behind and sits dejectedly on the curb while the others drive away.