Last Monday (July 31st) we were nearly surrounded by ice, which closed in the ship on all sides, scarcely leaving her the sea-room in which she floated. Our situation was somewhat dangerous, especially as we were compassed round by a very thick fog.

This is the start of a longer quote that is explained in depth in Quotes by Setting: The Arctic Ice. The quote describes the perilous situation facing Walton and his crew when they find Robert Frankenstein in the ice and hints at the fact that the conditions have by now tempered the unbridled enthusiasm about the North Pole that Walton had expressed in Letter 1.

We perceived a low carriage, fixed on a sledge and drawn by dogs, pass on towards the north, at the distance of half a mile; a being which had the shape of a man, but apparently of gigantic stature, sat in the sledge and guided the dogs.

In Letter 4, while his ship is stuck, Walton describes to his sister the strange sight he and his men spied in the distance earlier: an enormous, human-shaped creature commanding a team of dogs attached to a sled. It’s with this description that we get our first look at Frankenstein’s monster.

I said in one of my letters, my dear Margaret, that I should find no friend on the wide ocean; yet I have found a man who, before his spirit had been broken by misery, I should have been happy to have possessed as the brother of my heart.

In Letter 4, Walton excitedly informs Margaret of a stranger he and his sailors rescued from the cold, a man on a sled who had been pursuing the enormous creature Walton glimpsed earlier. This man, we will later learn, is Victor Frankenstein. Walton feels an immediate kinship with him, illustrating the significance of true companionship, which Shelley will continue to explore throughout the text. This, at long last, is the friend Walton has been searching for. He is elated to find Victor both curious and knowledgeable, traits the two men share. However, Walton also notes that Victor is “broken by misery,” suggesting a link between his suffering and his quest for knowledge, and foreshadowing the idea that his tale will be a cautionary one. While Walton has only begun his story, Victor is in the middle or near the end of his.