“Squeak. Squeak,” went Ysabell.

“By Wodan’s iron pizzle,” wailed Halfryta Hufflepuff, banging her large copper kettle with her long wooden ladle. “Not now, of all the misbegotten times, not now.”

Gabriel Gryffindor appeared cautiously in the doorway to see what had happened. He had been keeping out of Halfryta’s way since she had received her consignment of snails. She was going to make purple dye, and he didn’t want to be anywhere near if it went pear shaped and she looked for someone to blame, but Halfryta’s explosion was over something less serious: Ysabell, her mouse familiar, had reported that the Romans were on the march. Except it might be that serious after all: the Romans on the move threatened to interrupt dyeing the wool yarn.

“Stay calm, my dear,” said Gabriel. “Rachyl Ravenclaw has been sighted in the woods gathering mistletoe, and the two of us can do a little reconnaissance.”

Halfryta’s nostrils flared at the thought of Gabriel and that intellectual hussy on a scouting expedition while she was slaving over her kettle of snail extract and wool. Gabriel made a quick exit and hastened off to find Rachyl.

Two days later, Gabriel returned, but first things first.

“That’s marvelous, Halfryta,” he said, admiring the strands of purple wool yarn.

“Do you really like it?” she asked. “That large kettle lets me dye a huge batch all at once, and it all comes out the same shade. But what are the Romans doing?”

Ah, my practical Halfryta, he thought.

The Romans wouldn’t arrive for several days since they were marching along the course of the river. This gave them supply barges and flat land where they had the advantage.

“I can do one more batch of yarn, and Ysabell can organize her kind,” said Halfryta.

The big day found the two armies facing each other across a rolling grass land. As per protocol, the hundred most senior Picts stepped out front and mooned the Romans. The Picts reformed their line and waited expectantly for the Romans to reciprocate, but the Romans merely kept their ranks.

“Those Romans are not true gentlemen,” said the Pict war chief. “They have no manners.”

“They’re a young country,” said Halfryta. “Give them a hundred years to become civilized.”

That’s my girl, thought Gabriel, extending the benefit of the doubt to everyone.

The Picts and the enchanters stifled a yawn. Here came the standard Roman advance: a charge to javelin range followed by drawing the gladius.

Hundreds of yards of yarn rose to intercept the javelins – everybody admiring the uniform purple shade.

But something was going wrong. The strands of yarn unwound from the javelins which continued their flight.

“By Wodan’s brass balls,” wailed Halfryta.

“There’s magic a’foot,” yelled Rachyl, stepping forward to burn the deadly swarm out of the air.

No matter. Ysabell’s hordes, thousand and thousands of mice, scurried toward the legion, running up their shanks and nipping at their privates, whereupon the Picts slaughtered the Roman lead elements.

But something else was going wrong. The mice were fleeing in terror as a phalanx of snakes appeared.

“By Wodan’s tin buttocks,” wailed Halfryta.

Rachyl threw a descaling hex, and the serpents were writhing on the ground.

“Spells,” shouted Gabriel. “Spells. Neutralize their wizards.”

Gabriel and Rachyl hurled counter-curses for all they were worth while Halfryta and Ysabell reformed the mouse formation. The earth shook under the charge of the light brigade, and the Picts carried the day.

“A damn close-run thing,” said the Pict war chief.

Gabriel, Rachyl, and Halfryta went searching for the band of wizards that had nearly undone them. Under an oak tree, they found a bruised and battered young man.

“Was it just you?” asked Rachyl.

He nodded yes.

“What’s your name, lad?” asked Gabriel.

“Sevrin, Sevrin Slytherin.”

“You’re a Gaul. Why are you fighting for the Romans?”

“They have my family, my mother and two sisters, hostage,” said Sevrin.

“None of these Romans will return, and everyone will assume you’re dead,” said Rachyl.

The young Gaulish wizard looked at Rachyl with relief. She smiled. He smiled back.

Noticing the exchange and seizing the opportunity, Halfryta said, “I think we should rescue his family.”

“Would you? Would you really?” asked Sevrin.

“Yes, I think we should,” said Rachyl Ravenclaw, helping Sevrin Slytherin to his feet.

Prompt from MuseAmusant: purple yarn, mouse, copper kettle.