Convict 13 continues the bad luck theme began in One Week, as Buster is mistaken for an escaped convict set to be hanged that very day. The short begins on the golf links where Buster encounters a lady golfer (Sybil Seely). He chips a ball which bounces off the side of a barn, hits him in the head and knocks him out. Along comes the escaped con, who switches clothes with the unconscious Buster. Revived, Buster is in mid-swing when he notices his new duds. By this time, the prison guards are already upon him. Taking flight, Buster hitches a ride on a passing car...only to learn it's the prison warden's. How unlucky can one guy be? He jumps ship and eludes the ever-increasing search party, ducking into a large gated estate...only to realize it's the prison yard. There, the guards inform him convict 13 is set to be hanged today. The gallows are all set up and the other prisoners are in the stands, hooting and hollering like spectators at a ball game; there's even a concessions man selling popcorn and beer.
Meanwhile, the warden's daughter (also played by Seely) has taken pity on Buster and changed out the hanging rope with a bungee cord. Of course, when the floor is dropped, Buster bounces up and down and doesn't die. The crowd of prisoners is understandably upset.The prison brass next assign Buster to break up rocks, where he manages to knock out a guard. Sensing the opportunity, Buster switches outfits. At the same time, a huge inmate (Joe Roberts) is planning a mass breakout. He knocks down every guard that comes after him. Of course, Buster, now a guard, catches the brunt of Big Joe's fury. He manages to contain Roberts and is promoted to Assistant Warden for his troubles. But the prison riot is already brewing; Joe steals Sybil and the bloody riot begins.
Finding the bungee cord and a punching bag, Buster gets an idea. Recreating an old vaudeville act, Buster swings the cord with bag attached, around and around his head in circles, every pass coming closer to hitting the prisoner. It was the Three Keaton's most famous, and most dangerous stunt and Joe Keaton (Buster's father) recreates it with his son; he plays the prisoner who gets conked. Buster uses this technique to fell all the rioting inmates. But, in the melee, Buster is knocked unconscious by a hammer. He finds himself again on the golf course being awakened by the lady golfer. It was all a dream.
With the exception of the old vaudeville routine (an impressive and palpably dangerous stunt), Convict 13 is a weak entry. Golfing scenes were common fodder for silent comedy and the film comes across as derivative, something you know the innovation Keaton is better than. Dishearteningly, Seely's role is non-essential; it doesn't even really make sense (what prison warden keeps his daughter inside among the inmates?!) Roberts makes a splash as very effective--and scary, and gargantuan--heavy, but the 'it was all a dream' twist feels like a cheat and undercuts Roberts' effectiveness (he's not around during the golfing scenes, which implies Buster conjured him as an imaginary bogeyman.) Ultimately, the film is not one of Keaton's better efforts.