The Labours of Hercules (S13E04)

Following a vicious murder, Poirot, feeling responsible, falls in to a deep depression. Doctor Burton does all he can to revive the detective’s spirits. However it is the desperate plea of a lonely chauffeur to find his missing true love, which eventually makes Poirot feel he can return to work. The quest to find Burton’s soul mate takes the infamous detective to the Swiss Alps where fate, once again, plays its hand. (iTunes)