“The year was 1902, on the Caribbean island of Martinique,” Dr. Morales began. “The island’s capital is the city of Saint-Pierre, which is is right on the Caribbean Sea. And it sits right at the base of Mount Pelée.

“Pelée was a fairy-tale kind of mountain, with bright green slopes covered with trees.”

Like St. Helens, Jess thought.

“Few people realized that it was actually a volcano. It had rumbled a few times over the centuries. But it had been silent for more than fifty years.

“And then, in April of 1902, Pelée woke up. All through that month, there were hundreds of very small earthquakes.”

“Like the ones today?” Eddie asked.

Dr. Morales nodded.

“There was also the strong smell of sulfur gas seeping from deep inside the Earth. That gas builds up as a volcano is becoming more active, and it can leak out of the Earth. It has a horrific smell, like rotten eggs. Around Pelée, the stench became so strong that people fainted in the streets. Horses collapsed.

“But few had any idea that the quakes and the sulfur were warning signs that Pelée was going to erupt. The science of volcanoes was unknown back then. People simply didn’t understand that they were in danger.

“That changed in early May, when a small eruption sent ash and glowing rocks into the air. A few days later, part of the volcano broke away, and a river of boiling mud and ash roared down the mountain at eighty miles an hour.”

“That’s faster than my truck,” Mr. Rowan said.

“Some mudslides can travel even faster. That one killed more than one hundred and fifty people.” Dr. Morales said.

He looked at Jess and the twins.

“The story gets more grisly. Maybe I should stop here.”

“No!” Sam shouted. For him, this was even better than a Mariners game.

Dr. Morales looked at Mom, who nodded.

“Okay,” he said. “Because next come the snakes.”

“Snakes?” Mom said.

“The earthquakes disturbed thousands of snakes that had been living on the mountain. They came slithering down into Saint-Pierre. Some of them were venomous six-foot-long pit vipers. Hundreds of people died from bites.”

“Goodness, I’m going to have nightmares about this,” Mom said.

“Sorry,” Dr. Morales said. “I’m getting carried away. I should stop.”

But no way would Sam let him.

“It’s all right,” Mom said. “You might as well tell us how this ends.”

“I think we can take it,” Mr. Rowan agreed.

“So at this point, people were terrified, as you can imagine,” Dr. Morales continued. “Many people left by ship. But most couldn’t afford to flee, or had no place to go. And the leaders of Saint-Pierre kept telling people the worst was over.”

“I’m guessing they were wrong,” Mom said with a cringe.

“Very wrong,” Dr. Morales said.

“The real disaster happened on May 8, a cloud of sulfur blanketed the city. First there was a massive explosion. Pumice and mud rained down. And then a wave of searing hot gas and ash exploded out of the mountain and into Saint-Pierre.”

Dr. Morales took a breath.

“Within seconds, thirty thousand people were dead.”

Jess gasped. And the boys’ chins practically hit the table.

“Thirty thousand people?” Mom said slowly. “How is that even possible?”

“That was the pyroclastic surge. Imagine the wind in a hurricane, but with air that’s scalding hot. Then add toxic gas and ground-up rock and ash. The heat is so extreme that it burns everything in its path. People died instantly, without even knowing what happened to them.”

Nobody spoke for a moment, and even Sam looked queasy. The only sound was the gurgle of the soda fountain.

“And you’re saying that the same thing could happen here?” Mom asked.

Dr. Morales nodded. “It could. But luckily, there aren’t thirty thousand people living right at the base of St. Helens.”

That was true. The mountain was surrounded by forests, with just a few towns dotting the valley.

A chill came over Jess, even though she was warm and snug sitting between the twins.

For her entire life, St. Helens had been the beautiful mountain rising into the sky. She’d grown up hiking its winding trails, diving into its cold lakes, and fishing for trout in its streams. Just looking at St. Helens out her window made her feel calm, as if it were watching over her somehow.

Okay, maybe somewhere in the back of her mind she’d known that St. Helens was a volcano. Everyone around here knew that. But Jess never imagined that it was a real volcano, a killer that could explode.

“When do you think this eruption is going to happen?” Mom asked.

Dr. Morales shook his head.

“It’s hard to say for sure. But I do believe it’s going to erupt violently. And I think it’s going to happen soon.”