On Duty Alone is a double-length Christmas special episode of The Lenny Lego Show. it covers episodes 74 and 75 of the show's eighth season and is the first double length episode to be neither a premiere or a finale. It is also the second double-length episode in Season 8, the other being Lenny's Thanksgiving Kerfuffle.
The episode is a spoof of the Home Alone film series. Lenny Lego, who recently became a cop in the series, is left to guard the prison alone. Meanwhile, two burglars try to bust out their boss, who is being locked up in that same prison. The episode was released on December 24th 2014.
On Christmas Eve, town cop Lenny Lego is about to play Joseph in the annual Christmas Pageant, but realizes he must instead work the over-night shift at the prison, left to guard the prison alone. Shortly after hearing the news from his bnoss, Lenny goes out to his car to get his lunch. While doing so, Lenny overhears two burglars in a car next-door planning to bust out their leader, Mickey Stacos, from the prison. As the duo drives off, planning to return at 9PM, Lenny decides that he will set up some traps for the burglars to run themselves into while they attempt to bust out their boss.
Lenny offers to release Mr. Fireman, who is still in prison from the previous episode, if he helps set up the traps (after a failed attempt to convince him to pay a 15 dollar fine, which he claims to be saving for Mcdonald's). Lenny makes a list of supplies needed for the traps and sends Mr. Fireman back to downtown to get them. While doing so, he encounters Mr. Ambulance, who suspects something unusual about Mr. Fireman and demands to know what he's up to. In an effort to keep his plans a secret, he strikes Mr. Ambulance with a taser and hides his body in a nearby dumpster, then continues his mission.
The traps are set up and Lenny and Mr. Fireman hide as they witness the two burglars show up right on schedule. Upon arriving, the burglars run into nearly every trap that is set up for them (except for one trap, which Lenny's boss later becomes victim to). In the midst of all the fun, however, one of the burglars somehow pulls out a gun and demands that his boss be set free. However, the two are suddenly beaten up by Mrs. Diney, the town's oldest citizen, and Lenny arrests them shortly afterward. Lenny's boss arrives at the prison, after hearing about the commotion, and congratulates him for catching the criminals and awards him a bonus for doing so and working the night shift. Moments later, however, when retrieving a Christmas present he forgot to give to Lenny, he opens the closet door and flour poofs into his face. He has run into the only trap that the burglars did not discover. Lenny is immediately fired, but is then immediately taken back as Lenny's boss assumes the traps were responsible for the arrests of the burglars (Lenny is eventually fired for good some episodes later for being thrown into prison himself, thus setting a terrible example for the community).
The next day, Christmas Day, Lenny and his friends gather to celebrate the holiday. Lenny get's a call from Randy, who is at the airport about to travel to his family's for Christmas (This is because Randy's mom believed that the airport would be less busy on Christmas Day itself). Just before he hangs up and boards his flight, he tells Lenny on the phone that when he returns, he has a special surprise for him and everyone else. Randy must now go as his plane is boarding and hangs up. The episode ends with Lenny standing outside (with a still unconscious Mr. Ambulance in the background) breaking the fourth wall by asking the audience what they think the surprise could be.