Complex sentence: However, Lili soon discovers that she's falling in love with Larrabee and can't find the courage to betray him, and when Larrabee discovers Lili's secret, he refuses to turn her in.
Split into simpler sentences: However, Lili soon falls in love with Larrabee and cannot find the courage to betray him. When Larrabee discovers Lili's secret, he refuses to turn her in.