Pierre Michel (The Mystery of the Blue Train)

Pierre Michel is the attendant onboard Le Train Bleu. He had been told by Ruth Kettering that her maid was getting off the train at Paris. However, it was the maid herself who disguised as Ruth and made Pierre believe that she had gotten off the train.

Naming
Pierre Michel shares the name with another train attendant, Pierre Michel, onboard the Orient Express. They are probably two different characters.