False pretences - Carolyn Keene

Jack Broughton worked at Carson Drew's law firm. He also had a second, secret source of income: blackmail. But the scheme is dead and so is he. Nancy found his body in her father's firm and now she is looking for the killer. So who could have killed Jack Broughton? Blackmailers have few friends and many enemies, but the question is, which one killed him? Never before has Nancy been so desperate to find an answer. Rumours are rife in River Heights that her father is the culprit. Nancy has to work fast before her father's reputation and business are destroyed for ever.