Cooper is lost. Ever since his father left their family three years ago, he has become distant from his friends, constantly annoyed by his little sister, Jess, and completely fed up with the pale, creepy rich girl who moved in next door, who won't stop staring at him. So when Cooper learns of an unsolved mystery his sister has discovered online, he welcomes the distraction. It's the tale of a deadly train crash that occurred a hundred years ago in...

Frank and Joe solve a mystery involving a missing man, an abandoned airplane and giants in the desert.

An invitation from Cap Bailey, science teacher at Bayport High, to accompany him out West to Wildcat Swamp on an archaeological expedition triggers off a series of dangerous events for Frank and Joe Hardy. Just before they leave, a ruthless criminal breaks out of prison. Their famous detective father, who is tracking down a gang of freight-train robbers, suspects the escapee is part of the gang. Investigation leads him to believe that the robbers...

Billy Dickens discovers that his mysterious father lives in Montana, so this summer Billy will fly across the country, hike a mountain, float a river, dodge a grizzly bear, shoot down a spy drone, and save his own father.

Catholic-schooled seventh-graders Sophie, Margaret, Rebecca, and Leigh Ann help an elderly neighbor solve a puzzle her father left for her estranged daughter twenty years ago.

"With the help of some unexpected, and rather ghostly, allies, Lockwood & Co. must battle their greatest enemy yet, as they move ever closer to the moment when the earth-shattering secret of 'the problem' will finally be revealed"--

Emily and Aaron are sent on a top secret mission by King Neptune. The king has been having nightmares he doesn't understand and he knows only that Emily and Aaron must go to the Land of the Midnight Sun to avoid catastrophe. But when the friends arrive in this icy world of mountains and glaciers, they uncover a mystery more dangerous than they ever imagined. With the help of her best friends and a brave heart can Emily survive and fulfil her mission?...