Denis Egan is dead. He’s okay with that. It’s been five years since he died, and the place where souls go is actually pretty nice. However, something is standing in his way. His twin brother Matt can’t let go of him, and as long as the living are holding on to his memory, Denis can’t rest in peace. To uncover the truth about what happened, Denis teams up with Matt. But visiting for too long has painful consequences for Denis, and Matt’s renewed interest in his brother’s passing is driving a wedge between his parents. Can the boys solve Denis’s death without breaking apart the family he’s left behind? 

It's been two months since the Kaplan family hunted down the Serpens relic, but when the evil Galina Krause suddenly and violently reappears, Wade, Darrell, Lily and Becca have no choice but to face her again. Now they must race to find an artifact said to be crafted by Leonardo da Vinci himself --- perhaps the strangest Guardian of all. Along the way, they uncover another layer to Galina's sinister endgame...and there might not be enough time to stop it.

As Becca and her family race through London, it's up to Becca to make sense of the strange time blackouts she's experiencing before the evil Teutonic Order beats them to the next relic. Or worse, hurts the people she loves.

The hunt for Copernicus's first relic sent Wade, Darrell, Lily, and Becca to the far reaches of the world and put them in serious danger. But they never imagined Sara Kaplan—Darrell and Wade's mother—would be kidnapped by the conniving Galina Krause. Now they must race the evil Teutonic Order to find the Serpens relic and rescue Sara before it's too late.

Wade, Lily, Darrell, and Becca fly from Texas to Germany for the funeral of an old family friend. But instead of just paying their respects, they wind up on a dangerous, thrilling, mind-blowing quest --- packed with puzzles, intrigue, and action --- to unlock an ancient, guarded secret that could destroy the fate of the world.

Loki is waging war, and Pinewood Bluffs is about to become his battlefield. Owen, Dana, Jon, and Sydney know they have to stop him. They'll do whatever it takes.

Owen, Jon and Sydney managed to rescue Dana from the underworld. But if they don't fulfill their end of the bargain with Hades, she might be headed back --- forever. As if that wasn't bad enough, some very creepy, very one-eyed mythological beasts are on the loose, ready to destroy the town. What chance do four kids stand against an army of mythological monsters?
 

Owen Brown's best friend, Dana, disappeared right in front of his face, turning his average life upside down. He's determined to find her --- before anyone realizes she's missing. Owen sets out on a mysterious, mythological rescue mission with his friends Jon and Sydney. But what none of them know is that Dana's disappearance is part of a much larger riddle.