Hercule Poirot has to book a ticket on the Simplon Orient train because he unexpectedly receives a telegram informing him of a development in a case he is currently working on.
So, the telegram demands his immediate return to London, disrupting his planned vacation in Istanbul. He realizes he must catch the next available train, which is the Simplon Orient Express departing at 9 pm that evening.
Hence, the concierge, Monsieur Bouc, initially hesitates to book Poirot a ticket, as it is already late in the evening and the train is quite crowded. However, recognizing Poirot's reputation as a famous detective, he makes an exception and manages to secure him a first-class sleeper compartment.
.Murder on the Orient Express
Why does Hercule Poirot have to book a ticket on the Simplon Orient train? Does the concierge anticipate any difficulty booking a coach at the last minute? Support your answer with quotes from the text