what was Nick's reaction to the series of events that are unfolding at this point?

Nick finds himself unable to sleep, since the terrible events of the day have greatly unsettled him. Wracked by anxiety, he hurries to Gatsby's mansion shortly before dawn. He advises Gatsby to leave Long Island until the scandal of Myrtle's death has quieted down.

Source(s): http://www.gradesaver.com/the-great-gatsby/study-guide/section8/