Sherlock, Jr. is one of Buster Keaton's funniest and most technically innovative features. He plays the floor sweeper and projectionist of a small-town movie theater who in his free time studies to be a detective. His troubles begin… More Sherlock, Jr. is one of Buster Keaton's funniest and most technically innovative features. He plays the floor sweeper and projectionist of a small-town movie theater who in his free time studies to be a detective. His troubles begin when he slyly buys his girlfriend a box of chocolates. Not wanting her to think him a cheapskate for only spending a buck on the gift, he carefully changes the price tag to read four dollars. Another fellow, also vying for the gal's affections goes one better and swipes the girl's father's watch and pawns it so he can buy her a really expensive gift. To cover his tracks, he takes the hock ticket and sticks it into the innocent Keaton's pocket and then makes darn sure the ticket is discovered. Naturally, the girl's family gives Keaton the boot. Now to restore his good name, he must use his newly acquired skills as a gumshoe. Sleuthing proves to be hard work, and after an entire day spent following his rival around town, the exhausted Keaton returns to his job at the theater and falls asleep during the showing of a sophisticated mystery. He then dreams that he and all the others involved in the "case" are involved in the movie, which deals with elegantly dressed people and the search for a purloined necklace. In his dream, he decides that the only way to solve his puzzling mystery is to enter the film and so he goes down to the screen and tries to jump into the movie. But something strange happens and he ends up appearing in various scenes from other films. Technically, Keaton accomplished this using some fast-paced and brilliant editing, so it appears that one moment he is alone in a desert and the next he is nearly mowed down by a speeding train that comes out of nowhere. The brush with the train lands him atop a cactus that suddenly transforms into an island. He attempts to dive into the water, but ends up in a huge snowbank, and from there he finally makes it into the movie where he finds his normal clothes magically changed into a tuxedo. In this way, Keaton becomes a character of the actual film as world-renowned detective Sherlock, Jr. A series of crazy chases ensue until a car crash awakens the sleeping projectionist. Groggily opening his eyes, Keaton is surprised when his girlfriend arrives, and she begs him to forgive her for doubting him. From there the bewildered fellow, happy to have her back but confused about what to do, glances at the still-playing movie and takes his cues from there. While filming a scene that takes place in a train yard, Keaton's neck was fractured in real life when he was slammed to the railroad track by the gushing water from the water tower to which he was clinging. Keaton left the scene intact for the film.