I am going to analyzed the fourth part of the ballad: The rime of the Ancient Mariner.

 In the first quatrain the Wedding-Guest and he is scared by the mariner (I fear thee, ancient Mariner) and  he gives information about him (skinny hand, art long, and lank, and brown, glittering eye, skinny hand, so brown).The fear of the Wedding Guest is emphasized by the anaphoric construction .

 In the second quatrain ,at line 7 you can find the voice of the mariner, he use  the imperative (fear not,fear not,thou Wedding Guest!)  and in the third quatrain he repeats the word alone twice and also the repetition of wide  underlines the mariner's suffering.The word alone is  in antithesis to the wide sea, the author emphasized the solitude of the mariner in front of the "wide sea".

From line 13 to line 16  the story of the crew: the mariner is alive, but the others are dead. There is the  opposition between death (the crew) and the living fauna of the sea.In line 15 there is an hyperbole to make more contrast with the men that are dead, the slimy things are alive instead the crew is dead.

The mariner is sad because animals are alive and his crew is dead, we can find a sense of nausea: looked upon the rotting sea, and drew my eyes away; I looked upon the rotting deck and there the dead men lay.

In the the 6^th quatrain there is a reference to religious code (I looked to heaven, and tried to pray) and also a curse (But or ever a prayer had gusht, a wicked whisper came): but he isn't able to pray.

His heart is "dry as dust" as the heart of the crew that is dead.

 In the 7^th line  you can understand the mariner's desperation: "closed my lids, and kept them close, and the balls like pulses beat.." in line 25 there is a chiasm to underline the difference between the sea and the sky. The sky in the religious code means salvation instead the sea ( the earth ) represents the sin.

The mariner looks at the bodies and their friends and" they look with which they looked on me had never passed away. They appear as if they were alive."

The mariner is the only one person alive and he has to live only with his dead crew as if it were a malediction:" an orphan's curse would drag to Hell a spirit from on high; but oh! more horrible than that is a curse in a dead man's eye! .the narrator repeted the number seven that is the number of the death.

  In the 10^th quatrain the speaking voice talks about the Moon: . There is an opposition between the Moon and the mariner's situation: the Moon is beautiful, and he is with deaths and the charmed water burnt always a still and awful red. Red colour recalls the colour of blood and death.

the moon "nowhere did abide": the moon, which is always followed by some stars, does never stop, it is described as a dynamic element ("the moving Moon") that does not give peace to the mariners for a long time.

But the moonlight allows the mariner to watch the water-snakes, which are "God's creatures of the great calm". By blessing them the spell begins to break and the mariner can come back home.

As a consequence, the light of the moon is what allows the mariner to rescue himself, because it let him to see deeper in the sea, that symbolically means seeing deeper in his coscience. This reminds the difference between enlightenment and romanticism: the enlightenment thinker thought that all can be understand towards reason, which is symbolically represented by the sun; the romantic thinker mantained that reason was not enought, you needed irrationality too, (which is symbolically represented by the moon), to be able to understand reality.

In the water the speaking voice can see the water-snakes: they moved in tracks of shining white, and when they reared, the elfish light fell off in hoary flakes. They can move and the crew can only stand still.

The creatures are beautiful and the mariner understands it: he blesses them and at the same time his malediction goes away (The self same moment I could pray; and from my neck so free the Albatross fell off, and sank like lead into the sea).