Spoiler Warning: The following bookmark contains plot information relating to The Crossing.
Don Arnulfo offers Billy the cryptic clue that he should place his traps in ‘Lugares donde el fierro ya ésta en la tierra… Lugares donde ha quemado el fuego’ ('Places where the iron is already in the earth… Places where the fire has burned'); in ‘such places that God sits and conspires in the destruction of that which he has been at such pains to create’ [p.47]. It will be the trap Billy places in the ashes of the vaquero’s campfire which finally catches the wolf.
In No Country For Old Men and The Road, fire is employed as a symbol of hope; but its more destructive elements are brought to the fore in The Crossing. Fire as a motif for destruction and apocalypse recurs throughout the novel, from Boyd’s dream of a lake of fire to the shadow of the atomic bomb towards the end.