Murder on the Orient Express
A is for the ARMSTRONG family, who lost their 3-year-old daughter, Daisy, to a kidnapper, who killed her in spite of collecting a ransom.
B is BOUC, who was the director of the Orient Express and asked Poirot to take the murder case of Ratchett on the Orient Express.
C is for CASSETTI, whose alias was Ratchett and had murdered little Daisy Armstrong.
D is for the DETECTIVE Hercule Poirot who solved the murder case of Ratchett and concluded that it was committed by the Armstrong family and friends.
E is for the EVIDENCE found on the body of Ratchett in his compartment, such as a handkerchief and a piece of paper with Armstrong written on it.
F is for the FOOTPRINTS not found in the snow outside the open window of Ratchett's compartment; the open window was meant to mislead others to believe that the murderer had escaped out of the open window.
G is for the GRUESOME murder scene in which Ratchett's body was discovered.
H is for the HANDKERCHEIF with the initial H monogrammed on it, found at the crime scene next to the body, along with other pieces of evidence.
I is for the ITALIAN (the Armstrong family's chauffeur) whom M. Bouc suspected the whole time to be the murderer.
J is for the JUSTICE that the passengers thought that they had delivered when they stabbed Ratchett to death.
K is for the KIMONO worn by a person seen in the hallway near Ratchett's room on the night that he was murdered.
L is for the LOVE felt by the passengers who were connected to the Armstrong family; these passengers all turned out to be the murderers of Ratchett.
M is for the MURDER of Ratchett on the Orient Express.
N is for the NEW compartment that Poirot was moved to, which happened to be next to Ratchett's.
DIAGRAM OF ISTANBUL-CALAIS COACH
O is for the ORIENT through which the train had to pass to get back to Europe.
P is for the PASSENGERS on the Orient Express who murdered Ratchett to avenge the death of the Armstrong family and had all either been employed by the family or were dear family and friends.
Q is for the QUESTIONS Poirot interrogated the passengers with to deduce who the murderer was.
R is for the RESTAURANT CAR in which Poirot conducted his investigation of the case and interrogation of the suspects after the murder.
S is for the SORROW that Daisy Armstrong's mother and father experienced after her death, which eventually led to their own deaths.
T is for the TERRIBLE cry that Poirot heard the night before Ratchett's body was found.
U is for the UNIFORM belonging to the Wagon Lit Conductor, found in Hildegarde Schmidt's bag, who used to be the Armstrong's cook.
V is for the VARIOUS alibis given by the passengers in the Istanbul-Calais coach, who knew the Armstrongs.
W is for the WINDOW left open in Ratchett's compartment, to stage an escape by the murderer.
X is for the XYPHOID PROCESS belonging to Ratchett, which could have easily been stabbed, considering the amount of wounds he received.
Y is for YUGOSLAVIA, the country that Ratchett was murdered in and where the train had stopped because of a snowdrift.
Travel Route of Compagnie Internationale des Wagons-Lits, or International Sleeping Car Company (Simplon-Orient Express in green)
Z is for the time ZONE that was crossed between the time of murder and the time that Ratchett's body was found.