Moriarty the Patriot (2020)

S1E21 The Sign of Mary

John presents Sherlock to his fiancée, Mary, leaving Sherlock taken aback. He soon senses that Mary is troubled by something deeper. She reveals six pearls that relate to her father’s mysterious disappearance and asks Sherlock for his help in uncovering the truth. However, it’s clear that she’s concealing some important information.