Black Mercury — Charlotte E. English

Caspar Goldstein: a rich, charming steamcar racer with a slight morality problem.Clara Koh: a smart, impoverished engineer-in-training with big dreams.He can't help getting into trouble. It's her unhappy job to get him out of it.When a mysterious substance known as black mercury arrives on the scene, Cas purloins some, because of course he does. With its power to supercharge his autocarriage, he's guaranteed to win the coveted Eisenstadt Cup. But soon he's got bigger problems, because that's not all the black mercury can do. Over confident and under prepared, Caspar makes an easy mark -- and he's up against the deadliest of assassins and thieves. Can a ragtag team of drivers and engineers survive, or will this adventure end in disaster?