Agatha Christie's Poirot (1989)

S2E2 The Veiled Lady

Poirot visits Lady Millicent Castle-Vaughn, the titular veiled lady, at her hotel in London. As her wedding approaches, she finds herself in a predicament with a cruel blackmailer named Lavington, who possesses a love letter she penned to a former suitor. Lavington demands a hefty sum of twenty thousand pounds for its return. Determined to help Lady Millicent, Poirot resolves to retrieve the letter personally, even if it requires him to disguise himself as a Swiss locksmith.