The five most popular story-related questions about Lazarus Season 1 Episode 4 'Don't Stop the Dance' are:

1. Who is the stockbroker that owns the club, and what is his connection to Hapna?
2. What role does the hacker Dr. 909 play in the episode, and how is he connected to Skinner?
3. How does the team infiltrate the club, and what challenges do they face during the investigation?
4. What is the significance of the club's nightlife setting to the unfolding of the plot?
5. How do the team dynamics and individual character interactions influence the progress of the investigation in this episode?

These questions focus on the episode's key characters, plot developments, and setting, excluding general plot overview or the ending details.