to know exactly what he is thinking and feeling at all times. She will panic if he is late getting home. She will dote on his every want, never allowing him “to be tired, to sit in a draught, or to neglect” his food. She will be hurt if he is unfaithful, but she will always forgive him. She will be his perfect servant.

Now think about this for a moment. Alan thinks it sounds wonderful. He is filled with joy at the very prospect. But reflect on what it would be like to live with this behavior day in, day out for the rest of one's life. It would become, at best, irritating, and perhaps even intolerable in a very short time. Alan would soon be driven nearly crazy by Diana's attentiveness if he gave her this potion and it actually worked. His life would never be his own again.

Yet Alan doesn't realize the consequences of his desires any more than someone who wants another person dead can see the long-range results of that longing. He is caught up in the moment, positive that he wants Diana's full attention, certain that the life the old man is describing is ideal. Further, readers might wonder how much Alan really loves Diana. After all, he is ready to essentially enslave her without thinking about the ramifications of that one bit. He is ready to change the woman he professes to love rather than accepting her for who she is and loving her anyway (or moving on if their love isn't true).

Indeed, Alan has not yet learned the meaning of the motto “Be careful what you wish for,” and the story ends before we find out what happens to Diana and how Alan will feel afterward. He thinks he is grateful to the old man, but perhaps he will discover that what he wished for is not at all what he needs.

A feminist literary scholar could have an absolute field day with John Collier's short story "The Chaser." Without needing to delve too deeply into the story, she could come up with an analysis that examined the blatant misogyny that courses throughout the story.

Simply put, "The Chaser" presents women as a problem. More to the point, it presents them as disposable, as a problem to be got rid of—if necessary, by means of the eponymous chaser, a deadly poison to be administered by men to their wives and girlfriends when they get too clingy or overbearing. Even the least radical feminist would have plenty to get her teeth into here.

The misogyny of the story is matched only by its corrosive cynicism regarding relations between the sexes, and this provides a further means of analyzing "The Chaser." Collier gives the impression that men and women, even if they fall head over heels with one another, are essentially enemies and cannot maintain cordial relations for any length of time, save in exceptional circumstances.

Such an attitude is personified by the character of the old man, who seems to know instinctively that anyone who buys his love potion will eventually return to get his hands on the "chaser."

A lot of younger people do not seem to understand why the story is called "The Chaser." The meaning of the title "The Chaser" is very simple, although the term "chaser" may not be as commonly used as it was when John Collier wrote his story. A chaser is a drink that is taken to follow the first alcoholic drink. The chaser may be alcoholic or non-alcoholic. For example, a person might drink a straight shot of whiskey and follow it immediately with a small glass of water to dilute the whiskey already in his stomach. One common combination at bars is a shot of straight whiskey followed by a small glass of beer.

The chaser in Collier's story is a poisoned drink intended to kill the woman who is suffocating the hero with too much love and possessiveness. The original drink was the love potion he bought to make her fall in love with him. The word "chaser" in this story has nothing to do with chasing anybody or being chased; it is another euphemism for the deadly poison the hero will probably be using to kill his wife.

Collier is telling a tongue-in-cheek story about love and marriage. He had a cynical attitude towards the subjects, probably because of his personal experience. A more serious assessment of marriage is to be found in Leo Tolstoy's classic story "The Kreutzer Sonata." Both writers thought that people think love will last forever and that most of them find that marriage is disillusining. Here is a pertinent passage from Tolstoy's story:

“We were like two convicts fastened to one chain, hating each other, each poisoning the life of the other and striving not to recognize the fact. I did not then realize that ninety-nine per cent of the married people live in the same hell as mine, and that it must be so. Nor did I then realize that it was so of others or true of myself."

In both Collier's and Tolstoy's stories men end up murdering their wives.

John Collier displayed a negative and cynical attitude about marriage in several of his stories, including "The Chaser," "De Mortuis," and "Back for Christmas." The theme of "The Chaser" is not about love but about marriage. Naturally marriage is usually the result of love, but it is marriage, not love, that results in such disillusionment that some people, according to the old man in the story, will result to violent means, as well as considerable expense, in order to escape from it. What is striking about "The Chaser" is not so much that the old man is selling a love potion but that he is offering a "chaser," or "antidote," or "glove cleaner" to counteract the effect of the love potion. It is an undetectable poison which the man may use to get rid of his wife without getting caught. Both "De Mortuis" and "Back for Christmas" are stories about a man who murders his wife and buries her in the basement. The old man's assessment of marriage is that it becomes too cloying and claustrophobic. Many other writers have expressed their disillusionment with marriage. One notable example is Leo Tolstoy and his story "The Kreutzer Sonata." Another negative assessment of marriage is contained in August Strindberg's collection of stories in two volumes titled "Getting Married."

Possible themes of "The Chaser" could be love vs. lust, infatuation, or the illusive power of love.

When Alan falls for Diana at some time before the story begins, he falls hard. He wants nothing more than to be with her all the time. Somehow he hears about a potion that will make her feel likewise, meaning she obviously doesn't now. So after giving her the potion, his feelings seem to fade, or he must get annoyed because he eventually goes back to the old man for "the chaser" a potion needed after the love potion to remove the effects of the love potion.

This theme applies to all love relationships because maintaining love after the "honeymoon" period is difficult for both parties. We value monogamy in our society and therefore determine that these types of fake attempts to fix the difficulties of a love relationship do not work. This is the intention of Collier's piece.

In my opinion, the theme of this story is love -- it is a story about the true nature of love.  The author is telling us that love is an illusion and that if we had someone truly act the way we think (when we are in love) that we want them to act, we would want to kill them or to kill ourselves.

In the story, the old man tells Austen about all the ways in which Diana will act once she takes the love potion.  Austen is really excited.  He thinks that it will be wonderful for her to be devoted to him and to him only.

But the old man knows that Austen will become miserable.  This is why he'll sell the love potion for $1 -- so that Austen will be back later for the $5000 poison.

So the theme here is that love (the way we think of it) is really a terrible thing and that a person who got it would soon regret having it.