From the very beginning, the Khalkis case struck a somber note. It began, as was peculiarly harmonious in the light of what was to come, with the death of an old man. Georg Khalkis, internationally famous art dealer and collector, died of heart failure. After his funeral, his attorney found that the will was missing and immediately called in the district attorney.
When Inspector Queen and his son, Ellery, are brought in to solve the mystery of the missing will, Ellery mentions the one place they have not searched for the will . . . the coffin! Upon exhumation of the Khalkis coffin they find that it contained not one body -- but two! 

"The Greek Coffin Mystery is a lively and well-constructed yarn containing unusual setting, ingenuity of plot, a surprise solution and legitimate use of the analytical deductive method."- Herald Tribune Books

Ellery Queen investigates the murder of a man who was found mysteriously buried in another man's coffin. There are many suspects, and as the story progresses the plot just gets more and more complex (for most mysteries it's the reverse). It is notable for its four separate solutions, that gradually emerge at the four separate climaxes of the novel, one at the end of each major section. The book demonstrates how much more complex life can be than one originally figures. It also shows how ideas can grow out of each other, gradually leading to more complex ideas. The real and final solution impresses by being "deeper" than the others, containing some very startling surprises. The final solution comes as a genuine shock--when I found out who the murderer was, I was momentarily tempted to throw down the book in disbelief. But Ellery Queen's careful deductive processes show that only (blank) could possibly have committed the crimes. This is an absolute tour de force, a must-read for mystery readers like myself who have, until this point, lived under the illusion that only English writers can construct ingenious plots. Ellery Queen has more than proven that the quality can be an American one as well.

In the early years there was an unsurpassed urge for symbolism in the work of Ellery Queen. The example most widely used to illustrate this is the fact that first letter of each chapter spelled the title of a book, but only in the Greek Coffin Mystery this was actually so. It does, however, illustrate the playfulness and attention the cousins took to detail.

"All I do know is that he has long seemed to me one of the very best detective authors now writing, and that I always grab every new story of his that comes along." - J.B. Priestley - Evening Standard

EQ is not an absurdist. The solutions seem logical and well developed, unlike Anthony Berkeley's multiple solution novel, The Poisoned Chocolates Case (1929).The novel is derived from E.C. Bentley's ¹   Trent's Last Case (1913) which has two solutions, and shows its detective failing to solve the mystery, with the true solution being only revealed by chance after the detective offers a false (if ingenious) explanation. Berkeley used this plot pattern repeatedly in his books, with numerous variations: both multiple solutions and failed detectives abound. Berkeley seems most interested in writing an anti-detective story, showing how each situation can be twisted to express a multitude of interpretations, mocking the idea of detective stories in general, and the ability to understand anything through reason. This sort of absurdism is very far from EQ's approach. EQ is instead interested in showing how reason can go deeper and deeper in a situation, uncovering profounder and profounder ideas. The closest analogy or model for EQ is scientific discovery, wherein a Tycho Brahe will make thousands of factual observations, a Kepler will then group them into laws, and a Newton will finally explain these laws through a system of universal gravitation. EQ's book is a fictionalization of this process, an attempt to create an imaginary situation that fully demonstrates the complexities of human reason.
EQ's later books are not formally organized around multiple solutions; in The Greek Coffin Mystery, the four solutions are the key structural underpinning and organizational principle of the book's design and storytelling. But he retains the technique of partial solutions growing into ever deeper solutions; it returns again and again as a key feature of his detectival technique. (Michael E.Grost)

According to JJMcC this case precedes the earlier publications and dates back to the years when Ellery was just graduated from college.

There is a challenge to the reader included.

1   E.C. Bentley was a British newspaperman. He only wrote four mystery books, but he was immensely influential and prestigious in his time. His reputation peaked around 1940