As the afternoon progressed, the animals of the sanctuary began to notice the change in the air.
Astra called her cubs with a low, guttural cough, her tail twitching nervously as she nudged them toward the sheltered overhang of the lower granite caves. The cubs, usually playful and oblivious, sensed their mother's tension and trotted close to her flanks.
The mountain stags stopped grazing along the meadow. The herd leader, a massive buck with twelve tines on his antlers, raised his head and tested the wind, his nostrils flaring as the temperature began to drop.
Lumina landed on a low boulder near the center of the pasture.
The snow-rabbits that lived in the rock crevices emerged from their burrows, their thick white fur fluffed up against the cold. They gathered in small clusters near Lumina's feet, drawing warmth from the radiant heat of her chest.
"The air is changing," whispered Astra, approaching the boulder with cautious steps.
Lumina tilted her head, her golden eyes meeting the big cat's pale green gaze.
"The northern ice is waking," Lumina replied, her voice sounding like the soft rustle of dry leaves over crisp snow. "It is not the winter we know."
"Can the pools stay open?" Astra asked, looking toward the Emerald Pool where the black ice rim had expanded by several inches in less than an hour.
"Not if the shadow reaches the Sunstone," Lumina said quietly.
The Sunstone was a massive monolith of amber-colored crystal located on the summit of Sunstone Peak, three kilometers above the sanctuary bowl. It acted as an amplifier for Lumina's fire, broadcasting thermal energy throughout the entire ridge.
If the Sunstone was covered in black frost, the connection between Lumina's core fire and the geothermal springs would be severed.
The stag leader trotted over to the boulder, his heavy hooves clicking against the stone path.
"The wind is growing heavy," the stag reported, stamping his hoof. "The young ones cannot endure a night in the open if the pools freeze."
"Gather the herd near the mouth of the Deep Caverns," Lumina instructed. "The inner warmth of the earth will hold for a time, but we must protect the entrance before nightfall."
The animals moved to obey without question.
The gathering of the herds at the mouth of the Deep Caverns was a disciplined, quiet operation.
Mountain animals possessed an instinct for survival that humans often overlooked.
They did not panic when the air grew cold or the wind changed direction; they observed the signals of the ridge and adapted accordingly.
Astra walked among the stags, her shoulder brushing against the flank of the herd leader as they organized the retreat.
"Move the fawns to the rear wall," Astra instructed the stag leader, her voice steady and commanding.
"The steam vents in the back chamber are the warmest," she added.
"And the water?" the stag leader asked, turning his head toward the central pool outside.
"Bring what you can in the wooden troughs," Astra replied.
"Once the entrance is sealed, we will rely on the inner springs."
Near the entrance of the cavern, a family of alpine marmots was busy transporting dried grass and berries into the rocky crevices.
Their small paws moved with frantic speed as they stacked their winter stores in the warmest nooks.
Lumina landed at the mouth of the cavern, her wings folding with a soft crystalline clatter.
The animals paused in their work, turning their eyes toward the great bird.
"The black frost is moving up the northern gullies," Lumina informed them, her tone grave.
"It will reach the sanctuary bowl before the sun sets."
The stag leader stepped forward, his antlers lowering in a sign of respect.
"What of the Sunstone, Lady Lumina?" he asked.
"If the Sunstone is smothered, the geothermal veins will freeze completely."
"I will ascend Sunstone Peak," Lumina answered, her chest glowing with golden light.
"I will hold the frost at the peak while you remain safe within the mountain's heart."
Astra stepped up beside Lumina, looking into the bird's golden eyes.
"The peak is wild during a frost-storm," Astra warned softly.
"You cannot fight the storm and maintain your fire indefinitely."
"I do not need to fight the storm forever," Lumina said calmly.
"I only need to ignite the beacon once."
She turned toward the dark clouds stacking up over the northern horizon.
The first flakes of black snow began to fall upon Aurora Ridge.
The stag leader was an experienced old buck named Silver-Tine.
He had led his herd through twelve winters on Aurora Ridge and trusted Lumina's guidance without hesitation.
"We will move the young ones first," Silver-Tine declared, stamping his front hoof.
"The cave is wide," Astra agreed, her tail swaying.
"There is room for all."
The snow-rabbits gathered their offspring into small groups near the rock entrance.
Their white fur blended seamlessly with the snow patches around the cave mouth.
Lumina hovered near the entrance, her radiant heat creating a warm corridor for the animals.
"Do not fear the dark," Lumina told the young fawns as they passed.
"The inner mountain holds the earth's warm heart."
"Will you be with us?" one fawn asked, halting at the threshold.
"I will be on the peak," Lumina answered gently.
"Guarding the sky."
The fawn nodded and stepped into the warm darkness of the cavern.
Astra took up her station at the door, her eyes scanning the darkening valley.
The sanctuary was ready for what was to come.