Ahah, you cry, what an excellent set-up! And so it is.
The train arrives in Paris and the seven persons mentioned are sequestered for questioning. And who are these suspects comes the question from the back row.
Well, there's General Sir Charles Collingham and his clerical brother the Revd Silas Collingham and a couple of Frenchmen -- Anatole Lafolay, who works in the precious gem line, and commission agent Jules Devaux. Italian policeman Natale Ripaldi, the English-born Contessa di Castagneto, and Dutch porter Ludwig Groote make up the international bunch being grilled like kippers by the French authorities.
The victim is an absconding Italian banker by the name of Francis A. Quadling, and certain evidence in his compartment suggests a woman visitor. This and other clues point to the countess as the culprit, but is she the guilty party?
Alas, once the circumstances of the murder are described, they provide the reader with the necessary hint that All Is Not What It Seems -- although there is still a bit of sleuthing to do to find out what happened and who was involved.
My objection is that so little is made of the characters involved. To think of the motives that could be introduced to muddy the international waters! The two Frenchmen could have been defrauded by the dead man, the countess might have been blackmailed by him, perhaps he was bribing the Italian policemen and threatened to tell his superiors when he tried to arrest him on the train. The Dutch porter presents problems but then the one who appears most innocent often turns out to be the person responsible. Perhaps the absconding cad ruined the Dutchman's daughter!
I thought it a pity so much suspicion is focused on the countess that other excellent possibilities are overlooked, particularly as this is a relatively short piece of fiction and there would have been room for a subplot or two. Even so, I liked the intriguing set-up -- I wonder what Christie fans would make of it! -- so I shall probably try another Griffiths and see if I am happier with the next novel.