Evan Ross backed into the corner of the den as he stared at his dog Trigger.

The tan cocker spaniel lowered his head and stared back at Evan with wet, brown eyes. The old dog’s tail began to wag excitedly.

“Trigger—” Evan cried angrily. “Did you eat Monster Blood again?”

The dog’s tail began wagging faster. Trigger let out a low bark that rumbled like thunder.

Evan’s back pressed against the dark-paneled den wall.

Trigger took a few heavy steps toward him, panting hard. His huge pink tongue, as big as a salami, hung out of his enormous mouth.

“Did you?” Evan demanded. “Did you eat more Monster Blood?”

The answer to Evan’s question was obvious.

Trigger had been normal cocker spaniel size that morning. Now the dog stared down at Evan, as big as a pony.

Trigger’s furry paws, the size of elephant hooves, thudded on the den carpet. His enormous tail pounded louder than a bass drum against the side of a leather couch.

Evan covered his ears as Trigger let out an excited, high-pitched bark that shook the den walls. “Stay! Stay!” Evan shouted.

The enormous dog panted hard, his tail wagging furiously.

Oh, no! Evan thought in horror. He wants to play!

“Sit!” Evan screamed. “Sit!”

But Trigger didn’t know how to sit. For ten years—seventy dog years!—Evan had tried to teach Trigger to sit on command.

But Trigger just didn’t get it.

“Where did you find the Monster Blood?” Evan demanded. “We all saw it disappear into thin air. Gone. It was just gone. You know that stuff makes you grow. And grow and grow and grow. Where did you find it?”

Trigger tilted his big head at an angle, as if trying to understand Evan’s words. Then, wagging his huge tail excitedly, he started to run to Evan.

No! Evan thought. He’s going to jump on me! He’s going to jump! If he jumps, he’ll crush me!

An enormous glob of drool escaped Trigger’s open mouth and hit the carpet with a loud smack.

“Sit!” Evan cried, his voice choked with panic. “Sit, boy! Sit!”

Trigger hesitated, staring down at Evan. To Evan’s horror, the dog was growing even bigger. Trigger was now as tall as a horse!

Where did he find the container of Monster Blood? Evan wondered, his back pressed against the wall. Where?

The dog’s brown eyes gaped at Evan like shimmering, dark pools. Trigger uttered another deafening bark that shook the whole house.

“Yuck!” Evan cried, squeezing his nose with two fingers. The dog’s breath rushed at him like a strong wind. And it smelled as sour as a dead mouse.

“Back! Get back, Trigger!” Evan pleaded.

But Trigger had never learned that command, either.

Without warning, the giant dog leaped at Evan.

“Down! Down!” Evan shrieked.

Trigger’s mouth gaped open. The dog’s huge tongue licked the side of Evan’s face. The tongue felt scratchy and hot. Evan’s carrot-colored hair was matted down with sticky dog saliva.

“No—please!” Evan screamed. “I’m only twelve! I’m too young to die!”

He started to scream again. But Trigger’s big teeth clamped around his waist, cutting off his breath.

“Trigger—put me down! Put me down!” Evan choked out.

The dog’s wagging tail sent a lamp crashing to the floor.

The teeth held Evan gently but firmly. He felt himself being lifted off the floor.

“Put me down! Put me down!”

Why wouldn’t the stupid dog listen?

Evan thrashed his arms and legs frantically, trying to squirm free. But Trigger held on tightly.

The dog’s enormous paws pounded on the carpet. He carried Evan through the hall and across the kitchen. Then he lowered his head and butted the kitchen screen door open.

The door slammed hard behind them. Trigger began trotting over the grass.

“Bad dog! Bad dog!” Evan cried. His voice came out in a tiny squeak.

Had Trigger grown even bigger?

Evan was at least three feet off the ground now!

“Put me down! Down!” he cried.

Evan watched the green grass of the back yard bounce beneath him. Trigger was panting as he walked. The panting sounds made Evan’s whole body vibrate. He realized his jeans and T-shirt were soaked from dog saliva. Trigger doesn’t mean to hurt me, Evan told himself. He’s just being playful. Thank goodness he’s such an old dog. His teeth aren’t very sharp.

The dog stopped at the edge of the flower garden in the back of the yard. He lowered Evan nearly to the ground, but didn’t let go.

His paws began to churn up the soft dirt.

“Let me down!” Evan shrieked. “Trigger—listen to me!”

Breathing hard, his hot, sour breath pouring over Evan, the big dog continued to dig.

A wave of horror swept over Evan as he realized what Trigger was doing. “No!” Evan shrieked. “Don’t bury me, Trigger!”

The dog dug faster, its front paws churning furiously. The soft dirt flew past Evan’s face.

“I’m not a bone!” Evan cried frantically. “Trigger—I’m not a bone! Don’t bury me, Trigger! Please—don’t bury me!”