In The Great Gatsby What happens immediately before the accident?

Before the accident, it is the scene in the Plazza Hotel. After a brunch at the Buchanans's , Daisy, Gatsby, Tom, Nick and Jordan decide to go to NY forced by Tom who sees languorous looks between his wife and Gatsby. On their way, they decide to stop at the Plazza Hotel. They rent a suit and then happens the conflit between Gatsby and Tom. Gatsby tells him that he has an affair with Daisy, that she has always love him and never Tom and that she will leave with him. But Tom doesn't feel in danger and let them both go back in Gastby's car to prove to Gatsby that he is not scared of him at all.