David decides to keep the news of Steerforth's tragic death from Mr. Peggotty and Em'ly. He enlists the aid of Mr. Micawber, who agrees (with characteristic flourish and oratory) to keep newspaper reports from reaching the group before they sail. David wants Mr. Peggotty and Em'ly to depart "in happy ignorance" for their new life in Australia.
David, his aunt, Agnes, and Clara Peggotty see them off, and David joyfully discovers that Martha Endell will accompany the group to Australia. Mrs. Micawber rounds up her children and recites her promise never to desert her husband. The ship begins to move and David waves goodbye to Em'ly and Mr. Peggotty standing arm-in-arm as the ship pulls away.
David then leaves England and spends three years traveling around the world. His sorrow over the loss of his wife increases daily, unrelieved by his journeys to different countries.
David receives a packet of letters from Agnes while he is in Switzerland in which she tells David that his sorrow must be his strength so that he can turn "affliction to good." David intensely returns to his writing and sends a story to Traddies, who acts as an agent for David. David's fame continues to grow, and he finally begins his third work of fiction. His mind begins to clear and his health improves. He decides to return to England.
Chapter 57 provides a welcome relief from the sadness and the pathos of the preceding sections. Dickens provides the reader with emotional variety and also shows that life goes on in the face of tragedy.
The shipboard scene is very effective. The ship's passengers, like the Micawbers and the Peggottys, are all seeking a new start. This optimism on the part of downtrodden, weary, and dispossessed people helps end the chapter on a happy note and conveys Dickens' firm belief in the inevitable triumph of good.
In Chapter 58, we see that David's special thoughts are still about Agnes. He realizes that he loves her, but he thinks that they will never be able to marry because of the brother-sister relationship that exists between them. These thoughts plague David's mind as he prepares to return home.