SOMETHING BIG AND snakelike suddenly lunged into the cave and wrapped itself around Smilus’s neck.

One moment the cat was a hairbreadth from me—teeth bared—and the next he was dangling in the air outside the cave.

“Mm … Mm … Mam?” he stammered.

“That’s right,” said a deep, rumbling voice. “Remember me?”

I scampered over to the cave entrance and looked up. A colossal reddish-brown mammoth had her trunk wrapped around the pop-eyed cat. Woolly was next to her—less than half the size of his mother, but scowling at Smilus just as fiercely. A dozen other mammoths were facing off with tigers around the clearing.

“What about Woolly’s father?” Mam demanded, bringing the squirming Smilus eye to eye with her. “Remember him?”

The big cat gasped for breath.

Suddenly, the tigress left Boss Hog and leapt at Mam, clawing a thick mat of fur off her left front leg with a terrible ripping sound.

Mam dropped Smilus, who landed on the tigress. Both cats yelped and staggered backward. The other mammoths charged. The cats leapt. The clearing echoed with roars, snarls, and yelps of pain.

Soon three tigers had Woolly surrounded.

“You pathetic hairball,” hissed Smilus. “Ready to die like your daddy?”

The mammoths were bigger and stronger, but the cats were more nimble and ruthless. They didn’t think twice about attacking the herd’s smallest and weakest.

Mam came rumbling toward them—scattering cats left and right.

They regrouped and ganged up on an old tuskless mammoth called Glacier. But it soon became clear that as long as Mam was around, the cats could never hold an advantage for very long.

Finally, six tigers trapped her against a cave wall, while the other six kept the remaining mammoths at bay.

Smilus crouched to leap for her exposed neck. “Any last words?” he sneered.

She looked around wild-eyed, but she was completely surrounded.

“Okay, Mam, time to say good-bYEOWWWWWWWWWW!” Smilus shrieked, feeling a tusk where no tusk should ever be felt.

He hightailed it into the trees as Woolly charged down the line, tusking every tiger butt in his path. Five more cats yowled and followed their boss into the jungle. Seeing their number cut in half, the rest disappeared just as quickly as they’d come.

At first, no one moved. We waited in our caves, listening. Had we really just been saved from certain death by a herd of shaggy behemoths? The four of us dashed out and hugged Woolly.

Soon, the other kids followed, gazing up in awe at the great beasts. Next came the women, shouting for the children to be careful. Finally, the men emerged, calling enthusiastically for a victory feast.

Unfortunately, the party would have to wait. We soon heard savage voices above us and saw the cats in the bare branches of the large gourd trees that surrounded our village.

Smilus’s big sinister eyes met mine. “Just wait until nightfall,” he hissed. “All you’ve done is delayed your own funeral.”

I looked at the sky and remembered last night’s tiny sliver of a moon. “If they come down tonight,” I said to Mam, “we won’t be able to see them.”

Mam nodded gravely. “They killed Woolly’s father on a moonless night.”

Echo glanced at Woolly, who was staring up at the treetops. “Mam,” she said, “is that when your son got separated from the herd?”

“A moon’s turn ago,” said the matriarch, “as we were heading south, the cats attacked us and killed Woolly’s father. My son got lost trying to run after them in the dark.”

“You!” shouted Boulder, pointing at Echo through the crowd. “You can talk to those … mammoth things, right?”

Echo’s eyes narrowed, but she nodded.

“Well, talk to that boss mammoth there,” he said, pointing at Mam. “They need to shake those trees and get rid of those cats now!”

Echo turned to Mam, but she had already understood.

“It’s not so easy,” said Echo, interpreting Mam’s words. “If we shake those trees, the cats will just jump into others.”

“He say! You do!” barked Bonehead, stepping out of the crowd. “My dad Big Man!”

“Not of our herd,” replied Mam. “We risked our lives to protect your clan, but only to repay your friends here for taking care of my son.”

Bonehead looked at Stony, Echo, Hamhock, and me. “Friends?” he scoffed. “Me rather be friends with cats!”

Mam spoke to the crowd this time. “If this is your future Big Man, then humankind is in big trouble,” she said.

Bonehead’s eyes nearly popped out.

“We’ve been moving south for months and haven’t seen a single human settlement that’s survived,” she continued. “A lot of bones in the snow, but that’s it. No one seems to have adapted to the tigers and the cold fast enough.” The throng grew around Mam as Echo interpreted her words. “I believe that the future of humankind depends on this group and the leader they choose.”

A hush went through the crowd.

Mam turned to the four of us. “Woolly told us how you helped him. If you wish to join our herd, you and your families are welcome. We will protect you. But only you.”

Bonehead sneered. “Go, Loony Lug! Go join herd!”

Echo gave me a look that said she was seriously considering it.

I shook my head at Boulder and Bonehead. “These are my people,” I said, gesturing toward the crowd of Macrauchenia Riders and Boar Riders watching us. “I’m staying right here.”

“Good,” said Boulder. “Because our clan is leaving!”

I stared at him. I hadn’t expected that.

“Macrauchenia Riders, follow me!” he boomed. “I know better caves! Hidden caves! Far from these nasty cats!”

The crowd stirred with excitement. Frogface and his wife, Birdbrain, immediately walked over and stood by the Big Man. They carried Bugeyes, who had recovered enough to shoot me a nasty look. Others began to follow. Then a familiar voice behind me announced: “I’m staying with Lug.”

I turned around to see my father step forward. As everyone watched, my parents and sister emerged from the throng and walked over to me. “I’m proud of you,” said my father, hugging me so hard I almost keeled over.

As soon as I caught my breath, I hugged him back.

“What a couple of weaklings!” jeered Boulder. “Like father, like son!”

My dad turned and looked at Boulder for a long moment. “Oh, go roll off a cliff,” he said.

A few people couldn’t help laughing.

Boulder’s face turned about halfway between red ocher and dodo blood. Then Stony’s family walked over to our side.

“Stupid traitors!” Boulder spat. He scanned the crowd menacingly. “Anyone else?”

To my amazement, Chip and Rock walked over to our side. Then their parents. Then several Boar Rider families. It wasn’t long before there were many more folks around us than around Boulder. I noticed that the Big Man’s forehead was starting to look as damp as a dewy leaf.

“Now, hold your stones, everyone,” he wheedled, flashing a little wooden smile. “I’m just trying to protect our clans here.”

“Well, then,” I said, “maybe you should stay and help out?”

Boulder glared at me, but it was Bonehead who spoke.

“PEBBLEHEADS!” he screamed at the crowd. “You follow Little Slug?”

“His name is Lug,” said my mother.

“Lug warned us—” said Chip.

“—about cats!” finished Rock.

“And he helped save us,” Boss Hog chimed in.

“What have you done for us, Bonehead?” asked my sister.

Bonehead suddenly leapt at her, but Boulder grabbed his son and held him back. “Come on!” growled our ex–Big Man. “Let them be cat food!”

And with that, Boulder and his little gang stomped off into the jungle.

I thought about running up to Bonehead and grabbing the stolen club my father had made for me, but I didn’t bother. I knew I’d need something much more powerful than that to stop the tigers, and I’d already gotten the best present I could ever get from my dad today.

I gazed up at the cats in the treetops. Then I looked around at all the people who had stayed with me to defend our village. I thought of Mam’s words about the future of humankind depending on the leader they chose. The strange thing was that they had chosen me.