The five people are a doctor who is a scientist, who does not believe in anything not material being scientific; a vicar who is a typical clergyman, who thoroughly believes in supernatural things until they are proved, when he becomes an agnostic; a young American who is a cad and a fool; a girl who believes in fairies and goes to Holy Communion, which is the one thing that depicts she has a certain amount of sense; a duke who ends every sentence with a quotation from Tennyson to Bernard Shaw.
These five people are influenced by a Pied Piper kind of fellow who calls himself a conjurer, and is rather too clever for the company.
Apparently the conjurer has been strolling about the garden when he meets Patricia, who thinks he can produce fairies. In due course the conjurer comes into the room, where he has encounters with the various occupants, who don't believe in his tricks; the conjurer is unlucky enough to meet the young American cad Morris Carleon, who is really quite rude to the conjurer and discovers (so he thinks) all the tricks except one in which the conjurer turns the red lamp at the doctor's gate blue. This so worries Morris that he goes up to his room with a chance of going mad.
The others beseech the conjurer to explain the trick; he does so, and says it is done by magic, which is the whole point of the play, that we are left to wonder whether it was by magic or by a natural phenomenon.
The conjurer gets the better of the parson, the Rev. Cyril Smith, who believes in a model public house and the Old Testament, and takes a good stipend for pretending to believe in the supernatural.
The result of the whole matter is magic, by which we presume the trick may have been done.
The play is in some ways a difficult one: we are left wondering whether or not Chesterton believes in magic; if he does, then the conjurer need not have been so upset that he had gained so much power of a psychic nature; if he does not, then the conjurer was a clever fraud or a brilliant hypnotist.
One thing is quite certain, Chesterton brings out the weaknesses of the dialectic of the parson and doctor in a remarkable way; he makes us realise that there are some things we really know nothing about; if lamps turn blue suddenly it may quite well be a 'Something' that may be magic and might be God or Satan; anyhow, it cannot be explained by an American young man; it is of the things that the clergy profess to believe in and very often do not.
It is, I think, undoubtedly a problem play, and I doubt very much if Chesterton knows what was the agency that did the trick, but I rather think that 'Magic' is a great play, not because of the situations, but rather because the more the play is studied the more difficult is it to say exactly what is the lesson of it.