"Believe in Lord Arthur. Believe in your Carp. We shall prevail." is a quote from Garth Nix's book Drowned Wednesday. It emphasizes the importance of having faith in trusted figures and allies during challenging times. The statement encourages perseverance and confidence in the face of adversity, highlighting themes of hope and resilience within the story.

In the context of the novel, the phrase symbolizes the characters' trust in their leaders and friends to overcome obstacles. It serves as a reminder that belief and unity are powerful tools in overcoming hardship, ultimately leading to triumph and success in their journey. The quote encapsulates the novel’s message of hope and collective strength.