The dashes in this long sentence set off a series of appositives. (An appositive is a noun or noun phrase placed beside another noun or noun phrase and used to identify or explain it.) What noun phrase is explained by the appositives?

The noun phrase that is explained by the appositives is:

"...then I was answered by a voice from within the tomb!"  

Explanation:

As stated above about an appositive, you will discover that the appositive, "...- by a cry, at first muffled and broken,..." explains the above noun phrase. It tells the reader the type of voice it heard from the tomb. A noun phrase is known as a phrase that possesses a noun (or indefinite pronoun) and performs the same grammatical function as a noun. These noun phrases can actually function as verb subjects and objects. It can also function as a predicative expression and as the complement of prepositions.

it should be repealed cuase its not fair