Lang Johnson’s fascinating book “Devil’s Breath” centers on the assassin Sera Dwari, a talented chemist. They intend to control the drug market with her invention, Devil’s Breath, under her father’s nefarious direction. She must overcome Cassius Batista, a millionaire who is unwittingly sponsoring their endeavor, as a challenge. Sera discovers that she is falling in love with Cassius when she is assigned to kill him. This results in a risky game where the distinction between fact and fiction becomes hazy and the stakes are extremely high.