Excerpt: 'The 39 Clues Book 4: Beyond the Grave'

July 1, 2009— -- Follow the latest adventure of siblings Amy and Dan, as they travel the world solving a trail of clues that will lead them to the source of their family's power.

In Book 4 of the "39 Clues" series, Amy and Dan search to figure out what's behind the rivalry between the Tomas and Ekaterina branches of the Cahill family. Unfortunately, it could take them into enemy territory.

Read an excerpt of the book below and head to the "GMA" Library for more good reads.

'The 39 Clues Book 4: Beyond the Grave'

There was a loud clang as the iron tomb door shut completely. The lights immediately went out. "Amy?" Dan whispered.

"I'm right here." Amy only knew Dan was inches away by the sound of his voice. It was so dark she couldn't see her own hand. She fought down panic. The darkness pressed against them like a living thing.

Dan felt his breath catch. Amy grabbed his hand. Normally, Dan would have pulled his hand away and said something like "Ew," but just then his sister's fingers felt good, even if they were kind of sweaty.

"Somebody shut the door," Amy whispered.

"Thanks for the tip, Miss Obvious," Dan whispered back. Suddenly, he heard a noise. Was it a footstep? Shuffling, as if a foot was being dragged along the dusty ground. As though wrappings were dragging behind . . . "Did you hear that?" Amy whispered.

"No," Dan lied.

DEATH SHALL COME ON SWIFT WINGS TO HIM WHO DISTURBS THE PEACE OF THOSE WHO SLEEP. Dan knew he was breathing dust. He could feel his lungs struggling. He heard his own wheezing in his ears. "Dan." Amy gripped his shoulder. "There's plenty of air. Do you have your inhaler?"

His sister's calm voice steadied him. He didn't know how she could be so calm, but it helped him. He knew how she'd panicked when she'd almost been buried alive. The Amester was getting braver all the time. He reached into the pocket of his shorts and brought out his inhaler.

Better.

The noise came again, terrifying in its soft menace. He didn't even bother saying he didn't hear it. He imagined a mummy, black holes for eyes, trailing linen. His brains had already been sucked out, and he was just a dead thing . . . reaching . . .

Slow down, he told his heartbeat. If this was a video game, you'd think it was way cool.

Another shuffling noise, closer still.

But it's not a game!

Whoever it was — person or thing — it was hunting them.

"We've got to hide," Amy whispered. "The burial chamber."

He didn't, didn't, didn't want to go back to the burial chamber. The thought of it froze his blood. But he followed Amy into the place the mummy had lain thousands of years ago.