If these stories could be portrayed in any way, it would be the mystery story combined with fairy tales. The Mysterious Mr. Quin is a collection of 12 short stories and The Harlequin Tea Set and Other Stories contains a short story, never published before in a Christie volume, about Satterthwaite meeting with Quin years later. Satterthwaite appears with Poirot in two cases: Three-Act Tragedy and the short story "Dead Man's Mirror." In her autobiography, Christie said that Quin and Satterthwaite were her two favourite characters. In fact, The Mysterious Mr. Quin was dedicated by Christie "To Harlequin The Invisible".
Mr Quin is a character who not only changes fortunes but can bring them too. In a situation where a character is down on their luck, it is within his power to bestow either a direct fortune such as a tax free lump sum or other cash endowment, or provide them with the means of creating a fortune for themselves. Obtaining the rights of an Agatha Christie novel would be a good example of this kind of gift.
Of all of the Christie personalities, Mr. Quin remains the most enigmatic. He is the most stimulating of the " investigators " for he is more magical and imperceptible than anything else. It's challenging to explain: he's a tall dark young man gifted with the power over minds and people's fortunes to be a "friend of lovers." This supernatural-like man works with the very perceptive Mr. Satterthwaite, who is basically an mediator of Quin. Through Satterthwaite (an elderly, dried-up man who's elf-like), Quin works his wonders. Quin always reminds his elderly friend that he has a role to play in the drama of life. Mr. Satterthwaite is impassioned for the arts: he is always at the theatre or at an art gallery. Satterthwaite is an admirer of Kew Gardens and was once in love in his youth.
Satterthwaite and Quin change the courses of people's lives by cracking murders and even averting marital disasters. Although Quin appears when least expected and vanishes similarly, he tells Satterthwaite that it is he who does the "conjuring tricks". Quin is always quick to remind Satterthwaite that it is he who actually elucidates the problems of mankind, not Quin. Quin believes in the past, because "there is no atmosphere in the present." Quin, as seen in one story, even has the power to summon death. In fact, Satterthwaite (and Christie herself) once defined Quin as "an advocate for the dead".