for the rose she wears, he places it sentimentally in his vest pocket and throws open the suitcase he has intended to carry to Little Rock. Instead of nickel-plated shoehorns, there are safe-cracking tools inside. In ten minutes, the safe door is opened and little Agatha saved.

Resigned to his fate, Valentine closes the suitcase and starts to leave the bank; however, he is halted at the door by Ben Price. Jimmy speaks to him and is resigned to his arrest, "I don't know that it makes much difference now." Ironically, however, Ben Price feigns unrecognition. 

"Guess you're mistaken, Mr. Spencer," he said. "Don't believe I recognize you. Your buggy's waiting for you, ain't it?
And Ben Price turned and strolled down the street.

Ben Price recognizes that what the warden has told Valentine is true:  "You're not a bad fellow at heart." Having observed Valentine's actions, the detective knows that Jimmy is in love and intends to "live straight." So, he grants the safe-cracker a reprieve, "a retrieved reformation."

Ben Price is an ace detective who is hot on the trail of serial safecracker Jimmy Valentine. Jimmy has only just been released from a prison stretch for doing the exact same thing, but already he is up to his old tricks again. He has cut a swathe through a number of Midwestern banks, displaying his trademark efficiency and skill in breaking open the safes and making off with their contents.

But after Jimmy winds up in a small town called Elmore, he renounces his former life. He settles down, establishes a shoe-repair business, and gets engaged to a young lady whose father happens to own the town bank. Jimmy writes Ben a letter telling him that he has given up his criminal ways and now wants to go straight. This is the main reason why Ben does not arrest Jimmy when he catches up with him at the end. Jimmy promised that he would stop cracking safes. Strictly speaking, he reneged on that promise, but there was a good reason for it—he only broke into the bank's safe to save the life of a child trapped inside. Among other things, this selfless act indicates to Ben that Jimmy meant what he said about putting his criminal past behind him. He leaves Jimmy to get on with living the rest of his life as a model citizen.

At the end of the story, Ben Price leaves without arresting Jimmy. The likely reason for Ben's strange behavior can be found in the story.

During a vault-showing at the Elmore Bank, a little girl, Agatha, is locked inside the walk-in safe. Agatha's mother is frantic with worry that her child will die in the vault. Meanwhile, Annabel, Jimmy's fiance, begs Jimmy to save Agatha. Even though he knows that he risks exposing his true identity, Jimmy makes the decision to use his tools on Agatha's behalf.

By saving Agatha, Jimmy demonstrates that he is a changed man. Essentially, Jimmy risks the possibility of going to jail in order to save a little girl's life. Because of his heroic actions, Ben Price chooses not to arrest Jimmy. This is why Ben walks away at the end of the story.

Ben Price is described as a big man who is strong and tough. This is noted at the end of the story to show that Jimmy Valentine would have no way of escaping from Ben if he were inclined to try to do so.

At the door a big man stood somewhat in his way.

Jimmy already had one tussle with the detective, which he lost. This is shown towards the beginning of the story, when Jimmy returns to his rented room after being released from prison.

There on the floor was still Ben Price's collar-button that had been torn from that eminent detective's shirt-band when they had overpowered Jimmy to arrest him.

Ben Price exists as a character in the story in order to represent the law in general. He is Jimmy's nemesis. Just as Jimmy is the best safecracker, so Ben Price is the best bank detective. Both are experts at what they do. Ben can tell from examining the looted safes that they are the work of Jimmy Valentine. There is no doubt that he could succeed in having Jimmy convicted for all three bank jobs by testifying as an expert witness that they had to be the work of the notorious Jimmy Valentine.

Ben Price investigated the scenes of the robberies, and was heard to remark:

“That's Dandy Jim Valentine's autograph. He's resumed business. Look at that combination knob—jerked out as easy as pulling up a radish in wet weather. He's got the only clamps that can do it. And look how clean those tumblers were punched out! Jimmy never has to drill but one hole. Yes, I guess I want Mr. Valentine. He'll do his bit next time without any short-time or clemency foolishness.”

Ben is a formidable opponent because he is not only strong, intelligent, and experienced, but he is also tenacious. He traces Jimmy all the way to Elmore, Arkansas, which is where Jimmy is living under an assumed name precisely because he wants to get away from Ben Price. So the bank detective has resources besides his strength, intelligence, experience, and tenacity. He must have contacts all over the country. He can put out the word that he is looking for a certain individual and will soon be told where to find him.

Jimmy is the protagonist in the story. Ben Price is the antagonist. It is necessary to have a protagonist and an antagonist who are equally matched in order to have a interesting and sustained dramatic conflict. Jimmy is the best in his profession, so O. Henry created an antagonist who would be worthy of him. Just as Jimmy is determined to reform and stay out of prison, so Ben is determined to catch up with him and put him back into prison. The big surprise comes when Ben has a change of heart when he observes the heroic sacrifice Jimmy makes by exposing himself to his fiancee and her whole family as a criminal when he uses his expertise to release the little girl who is trapped inside the bank vault.

Ben Price is a tough private detective. He could be described as Jimmy Valentine's nemesis. He could also be described as the antagonist in the story, with Jimmy, of course, being the protagonist. Ben sent Jimmy to prison once before, and he goes after him again when Jimmy is released from prison and quickly performs three safe-cracking jobs.

These were the days before the federal government became involved in protecting banks. When the Federal Deposit Insurance Corporation was created under the Banking Act of 1933, it gave the federal government the justification to prosecute bank robbers. The FBI now protects all banks covered by the FDIC, and the FDIC insures depositors for up to $250,000. But that was not the case in O. Henry's time. The banks had to hire their own protection, and Ben Price was one of the private agents who specialized in bank jobs. Just as Jimmy shows intelligence in burglarizing banks, so Ben Price shows intelligence in tracking him down.

The losses were now high enough to bring the matter up into Ben Price's class of work. By comparing notes, a remarkable similarity in the methods of the burglaries was noticed. Ben Price investigated the scenes of the robberies, and was heard to remark:

“That's Dandy Jim Valentine's autograph. He's resumed business."

In one of O. Henry's famous surprise endings, it turns out that Ben Price may be tough and relentless but that he also has a kind heart. He manages to track Jimmy to Elmore, Arkansas, where Jimmy is living under the assumed name of Ralph Spencer. When Price sees Jimmy saving the little girl locked in the bank vault at the risk of losing Annabel and going to prison for years, he changes his mind about arresting him. 

“Hello, Ben!” said Jimmy, still with his strange smile. “Got around at last, have you? Well, let's go. I don't know that it makes much difference, now.”

And then Ben Price acted rather strangely.

“Guess you're mistaken, Mr. Spencer,” he said. “Don't believe I recognize you. Your buggy's waiting for you, ain't it?”

The text of O. Henry's "A Retrieved Reformation" does not specify that Ben Price has any conflict to resolve. He seems highly motivated to catch Jimmy Valentine and see that he is sent to prison.

Ben Price investigated the scenes of the robberies, and was heard to remark: “That's Dandy Jim Valentine's autograph. He's resumed business. Look at that combination knob—jerked out as easy as pulling up a radish in wet weather. He's got the only clamps that can do it. And look how clean those tumblers were punched out! Jimmy never has to drill but one hole. Yes, I guess I want Mr. Valentine. He'll do his bit next time without any short-time or clemency foolishness."

When Price traces Jimmy to Elmore, Arkansas, however, he finds that he has changed his name to Ralph Spencer and appears to have reformed completely. At this point Price could be experiencing an inner conflict about whether to arrest Jimmy for the three safecracking jobs he performed after being released from prison, or whether to let him retain his new identity and his new life as an honest small-town businessman engaged to marry the beautiful daughter of the town banker.

This inner conflict might be compared to that of Jimmy Wells in O. Henry's story "After Twenty Years." When Jimmy realizes that the man he is talking to at the doorway of the drugstore is wanted by the Chicago police, he has a conflict about making the arrest because the man is his old friend Bob. But Jimmy Wells has been a member of the New York Police Department for years, and he has a sworn duty to see that Bob is arrested. The same is not true of Ben Price. He is not a policeman, and there was no federal protection of banks in those horse-and-buggy days. Ben is evidently a private detective who specializes in providing security for banks, possibly a member of the famous Pinkerton's Detective Agency. As such, he has more discretion than any detective employed by local, state or federal government.

Ben must have made inquiries about Ralph Spencer before he followed him to the bank. He has learned that Jimmy has become an upright citizen and respected member of the town of Elmore. Then Ben sees with his own eyes how Jimmy makes a noble sacrifice by using his safecracking tools and expertise to save the life of the little girl trapped inside the vault, and he decides on his own discretion to give Jimmy a break. Ben is not violating any oath. He feels he is doing the right thing because he is sure Jimmy is completely reformed and on his way to becoming a model citizen, family man, taxpayer, churchgoer, and pillar of the community. Ben is doing this as a token of respect and appreciation for Jimmy's reformation and heroic rescue at the risk of everything he has achieved in Elmore.