Frank and Joe solve a dangerous mystery involving a payroll robbery, a mine cave-in, a piano playing ghost and bobby-trapped helicopter.

Frank and Joe Hardy look for clues after their friend's father is accused of stealing a treasure.

Framed in the doorway of Hercule Poirot's bedroom stands an uninvited guest, coated from head to foot in dust. The man stares for a moment, then he sways and falls. Who is he? Is he suffering from shock or just exhaustion? Above all, what is the significance of the figure 4, scribbled over and over again on a sheet of paper? Poirot finds himself plunged into a world of international intrigue, risking his life--and that of his 'twin brother'--to uncover...

When game warden, Joe Pickett gets close to the truth about the outfitter murders and endangered species, his life and the lives of his family face terrible danger.

"Ten strangers are lured to an isolated island mansion off the Devon coast by a mysterious "U.N. Owen." At dinner a recorded message accuses each of them in turn of having a guilty secret, and by the end of the night one of the guests is dead Stranded by a violent storm, and haunted by a nursery rhyme counting down one by one ... as one by one ... they begin to die. Who among them is the killer and will any of them survive?"--Page 4 of cover.

Fenton Hardy, the famous private detective and father of the Hardy Boys, asks his sons to help him with his latest case involving a criminal named Snattman and the smuggling of stolen drugs.

When a hard-fighting detective arrives in Personville and finds that his client has been murdered, he decides to investigate local gangland activities.

Roger Ackroyd knew too much. He knew that the woman he loved had poisoned her brutal first husband. He suspected also that someone had been blackmailing her. Then, tragically, came the news that she had taken her own life with a drug overdose. But the evening post brought Roger one last fatal scrap of information. Unfortunately, before he could finish reading the letter, he was stabbed to death.

How odd, Anne Beddingfeld thought, that a stranger caught her eye, recoiled in horror, and fell to his death on the rails of the Hyde Park Underground Station. Odder still was a doctor in a brown suit who pronounced him dead and vanished into the crowd. But what really aroused Anne's suspicion was when she learned of the doctor's link to the murder of a famous ballerina, a fortune in diamonds, and a drug-lord embroiled in blackmail. Most frightening...

Rob Ryan, a detective on the Dublin Murder squad, tells that twenty years ago he was the only child found of three missing children in the wood and that he was near-catatonic with no memory of the event; now Rob investigates a case chillingly similar to this previous unsolved mystery.