After a long day which included an inadvertent balloon trip and a long hike through the Swiss Alps we find our feline travelers, Henri and Cassie, in their hotel room preparing for bed. Cassie has moved all the blankets to the middle of her bed to make a small hollow to curl up in. After kneading it to her liking our young kitten spins around several times before lying down, but the excitement of the day has left her unable to sleep.

“Please tell me a story,” she asks Henri, who lies stretched out on her own bed.

Henri sits up and looks over at her companion with a yawn. “Okay, but just a short one.” After a moment in thought, Henri’s eyes lit up. “My mother used to tell me stories about Dynamics Cat when I was a young kitten. He uses the power of dynamics to fight evil.”

Rolling her eyes, Cassie looked over at Henri. “Sounds like more physics stuff to me.”

Henri gave a slight laugh. “Maybe, but Dynamics Cat is so much more. He has super strength, super speed, and can even fly.”

Cassie liked the sound of that, even if she was still slightly suspicious. “All right, I’ll give it a try.”

With that, Henri began her tale.

Dynamics Cat, that defender of velocity and motion, is spending a relaxing day at the park with young Billy Harper. All around them the sound of people playing and birds chirping can be heard. However, as they continue on, the park grows eerily silent.

Looking around, Dynamics Cat sniffs the air. “He’s here,” he mutters fiercely.

“Who?” asks Billy while trying to stifle a yawn.

“My arch-nemesis, Mr. Inertia,” answers Dynamics Cat with a growl.

Fighting to keep his eyes open, Billy looks around and sees a man sitting on a bench a short distance away. “You mean the guy sitting over there?”

“Oh don’t let him fool you Billy,” warns our hero, “he’s not sitting, but at rest. The fiend!”

“We learned about inertia in school,” answers Billy, glancing over at Mr. Inertia. “It’s what makes an object either sit still or keep moving until some force acts on it.”

“That’s right, Billy,” Dynamics Cat replies while glaring at Mr. Inertia. “When Isaac Newton developed his Laws of Motion, he also created the concept of inertia. There has been conflict between motion and inertia ever since.”

“He looks harmless to me,” offers Billy as he lowers himself to the ground and lies on the grass.

“Harmless?” hisses Dynamics Cat. “He’s against everything I stand for. If he had his way all motion and acceleration would cease leaving the world a joyless wasteland.”

“Billy!” cries Dynamics Cat as the boy begins to snore. Muttering darkly, he marches boldly forward towards his foe, his cape blowing in the breeze.

“Mr Inertia,” he purrs menacingly, “once again I’m here to thwart your dastardly plans.”

The man slowly turns his head and lazily eyes the cat standing in front of him. “Oh hey, Dynamics Cat. Nice to see you again. Can’t a guy just rest without being accused of having evil plans?”

“Oh, just resting here, are you?” answers our hero. “Then how do you explain all the people and animals lying on the grass and doing nothing?”

Mr. Inertia gives a patronizing smile. “It’s a warm sunny day and we’re in a park. What else would people be doing here?”

“Very clever. Using a summer day in the park to mask your foul plot.” Grabbing Mr. Inertia with his paws, Dynamics Cat lifts him upward. “Well, your evil scheme ends now.”

“If you wouldn’t mind,” asks Mr. Inertia politely, “could you aim me someplace nice? Maybe up north or in the mountains where it’s cool?”

“Oh, I’ll send you someplace nice,” he whispers sarcastically. “How does outer space sound?”

Mr. Inertia laughs. “You tried that last time and was unable to throw me hard enough to reach escape velocity. Guess my inertia’s too much for you.”

Dynamics Cat remembered their last encounter all too well. His anger had made him forget to calculate the trajectory of his throw. He’d almost fallen into the same trap again.

In less than a second the dynamic calculations flash through his mind. "Not this time, Mr. Inertia."

Facing southward, Dynamics Cat imparts an initial velocity of 10,000 feet per second to Mr. Inertia and he flies out of sight. “Hope it’s nice and warm where you end up,” he calls after him.

As Mr. Inertia hurtles away, the people and the animals in the park awaken from their slumber. Soon the park is once again filled with the sounds of people playing and birds singing.

Billy runs up to Dynamics Cat. “Are we safe now?”

Looking up at the sky, Dynamics Cat shakes his head. “For the moment Billy, but he’ll be back. Inertia can be very alluring, but it’s a trap.” With a sigh, he continues. “Mr. Inertia may have once been normal, but inertia has warped him and made him an enemy of all that moves.”

“That’s very sad,” observes Billy.

“It certainly is, Billy,” answers Dynamics Cat, patting his arm. “However, it needn’t ruin our day. My friend, Professor Branch, is at the other end of the park launching model rockets with his students. I may have asked him to save an extra one for us.”

“Wow!” cries Billy. That’d be great. Thanks, Dynamics Cat!”

Finishing her story, Henri leans back contently. She’d been pleased to see Cassie listening intensely while giving little purrs of excitement. With a smile, she asked, “so what’d you think?”

Cassie clapped her paws together. “I really liked it, especially when Dynamics Cat threw Mr. Inertia. I would’ve loved to see that.”

“I’m glad,” answered the Henri wrapping her blankets snugly around her.

Cassie stared at Henri with wide eyes. “Is inertia really as dangerous as Dynamics Cat said it was?” she asked.

“Oh no,” answered Henri with a chuckle, “inertia can’t make someone evil or anything like that. However, it does have a big impact on how much force it takes to move something. Earth has so much inertia there’s no way we could ever move it, but a small ball has so little inertia you can move it with ease.”

Cassie nodded. “So if the Earth had no inertia you could at it around like a ball? Wow, that’d be fun.”

“Yes,” answered Henri, “but the Earth and everything on it would shoot off into space since gravity wouldn’t affect it. Without inertia, any force, no matter how small, would send you hurtling away.”

“I don’t think I’d like that,” said Cassie.

“Neither would I,” responded Henri. “Now time for bed.”

Cassie looked at Henri with big eyes. “Could you please tell me another Dynamics Cat story?”

Henri smiled to herself, but held firm. “We’ve got another busy day tomorrow so we need to get some sleep. However, I’m sure we can find time for more Dynamics Cat stories in the future.”

“Hooray,” yawned Cassie blissfully. Curling up in a ball, she was soon asleep with visions of Dynamics Cat filling her dreams.