Laurel and Hardy play two policemen on night patrol, hence the title. They are given instructions to investigate a reported break-in but in the process of gathering the details from HQ they stumble upon a would be thief who is attempting to crack the safe cracking of a small store. Laurel mistakes him for the store owner, even going so far as to give assistance in the safe cracking, when Hardy enters to see what is keeping Laurel the boys manage to work out that the thief is not the store owner and rather than arrest him order him to appear in court at a date to suit the criminal. The boys head back to their car only to find the same thief attempting to steal it, angered Hardy insists that he must 'appear Tuesday' after all (a day the criminal is planning a bank robbery).