London, 1885. Gabriel Utterson, a seventeen-year-old law clerk, has returned to London for the first time since his life—and that of his dearest friend, Henry Jekyll—was derailed by a scandal that led to his and Henry's expulsion from the London Medical School.

Gabriel has a chance to start again, but he doesn't want to move on—not without Henry. Then Gabriel meets Hyde, a a strange young man with white hair and magnetic charisma. Gabriel can't help but grow jealous at Hyde's apparent closeness with Henry, especially as Henry continues to act like Gabriel means nothing to him.

But the secret behind Henry's apathy is only the first part of a deeper mystery that has begun to coalesce. Monsters of all kinds prowl within the London fog—and not all of them are out for blood...