Many of the characters in Mortal Engines seek power in one form or another. Whether for personal reasons or dominion over others, these power-motivated journeys result in loss and grief. Through Crome’s use of MEDUSA, Valentine’s desire to keep his social status, and Hester’s revenge arc, Mortal Engines explores how the quest for power only hurts us.

After Crome discovers MEDUSA’s existence, he lusts after it and what such power could do for London. As the mayor of a once-great predator city that has lost steam, Crome doesn’t consider MEDUSA’s negative destructive capabilities; he sees only its potential to restore London to its former glory. In his quest to get the weapon working and reach the barrier wall to the Anti-Traction cities, Crome lets the lower tiers of London fall to ruin and ignores the suffering of thousands. Crome’s quest for power ultimately leads to an accident that causes MEDUSA to destroy London. The work he does to honor his pride for London is lost because he refuses to consider another way that doesn’t involve mass destruction. His desire for power destroys the city he loves.

Valentine also seeks power—but on a more personal level. He was once a mere scavenger who would sell technology to cities in exchange for scraps of what those cities could offer.