Complex sentence: After Weronika sacrifices everything in the pursuit of a singing career, Véronique abandons her own similar goal because of poor health and attempts to find an independent course for her life, while becoming involved with a manipulative man who is fascinated by clues to her double nature.
Split into simpler sentences: After Weronika sacrifices everything to pursue a singing career, Véronique abandons her own similar goal because of poor health. Véronique then becomes involved with a manipulative man who is fascinated by clues to her double nature.