The quote illustrates a deep sense of anxiety and urgency experienced by the speaker. The imagery of a "taut heart" conveys a heightened emotional state, while the metaphor of a "sack in a cart" emphasizes a loss of control. This suggests that the speaker feels overwhelmed by impending doom, akin to a cart rolling downhill uncontrollably. The reference to a "cliff" and "abyss" reinforces the fear of an inevitable plunge into darkness.

In this moment of despair, the speaker expresses an inability to halt this descent, reflecting a broader theme of helplessness in the face of life's challenges. The vivid language evokes a visceral response, drawing readers into the character's turmoil. Nabokov's deft use of metaphor captures the essence of existential dread, illustrating how the pressures of life can lead one to feel as if they are hurtling toward a perilous outcome.