Why does this Coleridge passage appear in Frankenstein ? Like one who, on a lonely road, Doth walk in fear and dread, And, having once turned...

When Mary Shelley was 8 years old, she heard Samuel Coleridge recite "The Rime of the Ancient Mariner" in her parent's home. Mary Shelley was heavily influenced by the poetry of Coleridge, and Frankenstein is rich with allusions to "Rime of the Ancient Mariner." This excerpt from the poem parallels Victor's mood and actions. At this point, Victor is wandering the streets alone, contemplating the deaths of William and Justine, and his implicit guilt.  Of course, the shadow of his creation in constantly haunting him, and may well be following him down the road in this moment.

In the Gothic sense, Victor relates to the Mariner’s isolation and fear. In the Romantic sense, both the Mariner and Victor want the knowledge; however, unlike the Mariner, Victor’s new knowledge brings a curse along with it. Like the Mariner, Victor will live in isolation and fear. He seeks to tell his story to anyone who will listen, which turns out to be Walton. Walton is a mirror of the listeners of the Mariner's story in the poem. Thus Victor fulfills the comparison to the Mariner, haunted by his knowledge and his actions, tormented by his past.