I consider this to be one of L&H's funniest films. Liberty and most other L&H short films are easily worth buying at the same price you would normally pay for a full-length film, because there are more laughs in 20 minutes than there are in most full-length comedies.
The plot has L&H escaping from prison, and they quickly change out of their striped prison uniforms and into their regular clothes while being chased by police. In their haste, each one accidentally puts on the other's pants. They look for a place to change their pants, while inadvertently being caught repeatedly with their pants down in public places.
One of several places they duck into to change is the elevator to a building under construction, where Stan accidentally hits the lever, bringing them up to the top floor.
There are very few comedy films of any era that can compare to those of Laurel and Hardy, and this is one of their best.