Conversation so far:
who was the murderer in the movie in the heat of the night
Ralph robbed and killed Colbert.
why did Ralph kill Colbert in In the Heat of the Night
Ralph had gone to ask Colbert for a job at the new factory, but ended up attacking him and taking his money.
does Ralph get arrested in In the Heat of the Night
Ralph is arrested and confesses to Colbert's murder.
who are the other characters in In the Heat of the Night, besides Ralph
In the Heat of the Night tells the story of Virgil Tibbs, a black police detective from Philadelphia.

Question: what happens in the plot
Self-contained rewrite: what happens in the plot of In the Heat of the Night