In the short story "After Twenty Years" by O. Henry, two friends have gone their separate ways but have agreed to meet back at a certain place and a certain time after 20 years have passed. Since they last met, Jimmy Wells has become a policeman, while Bob has engaged in criminal activities and is a wanted man.

As the story opens, Jimmy Wells meets his friend Bob at the appointed spot in his policeman's uniform, but he does not identify himself. They begin to converse, and as Bob lights a match, Jimmy sees his face clearly and recognizes him as a criminal who is wanted in Chicago. They talk some more, and Jimmy leaves without telling Bob who he really is.

Later, a plainclothesman goes to meet Bob and pretends to be Jimmy Wells. Bob falls for the deception until they walk into the bright light of a drug store, and Bob realizes that the man with him is not his friend Jimmy.

Jimmy explains why he has sent the plainclothesman to apprehend Bob instead of doing it himself in a note that the plainclothesman gives to Bob. It says:

Bob: I was at the appointed place on time. When you struck the match to light your cigar I saw it was the face of the man wanted in Chicago. I couldn't do it myself, so I went around and got a plain clothes man to do the job.

We can see by this note that Jimmy sends the plainclothesman to Bob because of the friendship that Jimmy still feels for him. He doesn't want to arrest his old friend, but he knows that it has to be done, so he sends someone else to do it.