The five most popular story-specific questions about The Stolen Girl season 1 episode 5, excluding overall plot and ending, are:

1. What past events led to the kidnapping of Lucia?
2. What is the nature of Elisa's relationship with Marcus and how does it impact the story?
3. What details are revealed about the accident involving Rebecca's family and Marcus?
4. How do Elisa and Selma go about finding Rebecca, and what obstacles do they face?
5. What happens during the confrontation between Elisa and Nina (Rebecca) in this episode?

These questions arise from the episode's focus on revealing backstory, character relationships, and key confrontations that clarify the mystery at the heart of the drama.