According to a book published in 2007 titled "Route 66 The Television Series" by James Rosin, the episode of Naked City titled "Four Sweet Corners" was a mini-pilot for the Route 66 TV series.
Herbert Leonard and writer Stirling Silliphant had the idea for the Route 66 series while they were producing the Naked City program.
They had also decided on George Maharis as one of the leads.
This episode begins with the Maharis character who has just completed his military service, returning to his mother's apartment in NYC. His army buddy, played by Bobby Morris, tags along.
Maharis is shocked to learn that his little sister has grown up fast and is involved with a shoplifting ring. She is arrested but refuses to give the name of the ringleader. Maharis and his buddy track down the ringleader themselves. His sister says she has learned her lesson and will turn over a new leaf.
Maharis' mother pleads with him to stay, but he says he can't. He doesn't know exactly why, but he feels there is more of the world that he has to see. He and his army buddy walk away from the apartment building as it begins to snow.