'Passenger from Calais' Summary

The Engadine express, bound for England from Calais, carries an unusual passenger list: Colonel Basil Annesley, a retired army officer, and a mysterious woman with a maid and a baby. The woman, visibly apprehensive, fears she is being followed. Her unease piques Colonel Annesley's curiosity, and he becomes determined to uncover the truth behind her anxieties. A chance conversation reveals a suspicious package, leading Colonel Annesley to suspect the lady's secret may be far more dangerous than he initially imagined. He enlists the aid of two private detectives, adding another layer of intrigue to the unfolding mystery. As the train barrels towards its destination, Colonel Annesley races against time to unravel the secrets of the lady and her enigmatic package, confronting danger and deciphering a web of deceit that could have dire consequences.