Invasion Force by Katharine Tyndall

This is the story of how Clathrus archeri, the “devil’s fingers,” came to Europe from Aotearoa New Zealand. The fungus was first sighted in Europe in the Vosges, a mountain range which saw the earliest battles of the First World War. At present they are found all over Europe, their invasion fueled by the warming climate. The same warming threatens their survival in their native range. Someday, the devil’s fingers may only exist where war planted them. 

May 1914

The devil's fingers emerge from the floor of the evergreen beechwood as a carpet of pink fungal tentacles. The flesh of each is puckered and pitted like a tongue, unfurling sticky with spore-laden black gleba, the unripe fruiting bodies forming in stone-gray sacs. Clusters of sacs lie waiting under the sparse fallen leaves of the Aotearoan forest, and, as they burst forth, the air is heavy with the smell of rotting flesh. It is easy to imagine them as the hands of the dead, the sticky pink fingers of corpses carrying the scent of the underworld, as if beneath each reaching hand a putrefying body lies in wait to grasp at the ankles of passersby.

Black flies are drawn to the aroma, landing with delicate feet in the gleba and dipping their proboscides into the muck. Thousands of flies throng on the fruiting bodies, lapping the gleba until each tentacle is stripped bare. Disbursed of its spore, the fruiting body shrivels and decays into humus. The flies cannot eat all of the trillions of spores contained in the gleba—much of it clings to their feet and bodies. They buzz from fruit to fruit, spore mixing in their promiscuous landings. When the bacchanal is over, they fly on in search of more pungent pasture.

They find it on the bodies of sheep grazing near the beechwood. Autumn finds the flock fat and filthy, fleeces laden with a summer’s worth of mud and dung. Each animal’s body is a forest of detritus for the flies to explore. Flies land on the gray-white backs in search of clinging shit, crawling with their spore-coated feet through coils of fur. Droplets of gleba dislodge in the matted hair, and, as the fleece continues to grow, the spore is protected in a layer of sweat and oil from the animals’ bodies.

Normally the sheep would be shorn in the spring, when the fleeces had served their purpose of protection from winter wind and weather. But at this moment, across the world, demand for wool is ravenous. In beechwoods oceans away, humans are felling trees and digging trenches, burrowing themselves into the skin of the earth like ticks, bursting with blood when their bullets strike. The fighters need uniforms, and uniforms need wool, and in Aotearoa, the sheep have had since last August to grow their fleece. Prices have never been higher as the war effort consumes every available resource from the living earth. This winter, the sheep will shiver in their winter enclosures. The hair of their bodies is needed for the war a world away.

The sheep are accustomed to shearing, so they do not balk when they are rounded up in the hundreds, bleating at the smell and feel of the teeming herd. One by one they are pulled from the ranks by summer-burned arms, held wriggling, flipped and stretched as the shears slice over their skin. Naked and cold, they are loosed into an enclosure where they huddle against the chill. Now the shearing is revealed as strange. Whereas the spring shear leaves them light and cool in the summer heat, the fall shearing has stripped them of their winter coats. Uncertainty murmurs through the flock and they press close together. The pile of dirty fleece grows higher.

The fleeces are thinner than usual from the lack of winter growth, but soon the dust-colored mound of wool rises high over the shearing floor. Pitchforks and hands gather up the stinking wool into carts, and the carts feed into a hopper, and the hopper binds the fleeces into thick bales for transport to the place where they will be processed into thread by rumbling machines. The bales travel by cart and truck on muddy roads to the mill, and hands cut the bales open and the wool is dumped into great baths. In the haste to get the wool from the backs of sheep to the backs of men, everything is done in a tremendous hurry. The water heated by coal-fired boilers cleans the wool twice, enough to render it off-white, but not enough to strip the spores of the devil’s fingers from the fibers. Microscopic stowaways cling to the wool as it is carded and combed by the great racket of machines. Too small to be disturbed or injured by mechanical means, the spores are spun into the thread, then woven into the cloth. When the cloth is boiled or dyed some of them are killed, but by now the fabric is imbued with the labor of millions of flies, carrying trillions of spores. The lengths of cloth are cut into bales and blankets and sent by ship to the war, oceans away. Enough wool fabric is produced to stretch the length of Aotearoa’s North Island, and within its weft are the spores of an oncoming invasion.

What machines wove only human hands can cut and sew. In the factories of France, layers of thick woolen cloth are cut together into the shapes of disembodied arms and legs. Feet on pedals, fingers on the dials of machines craft the wool into dull-colored uniforms, in standard shapes to fit the averages of millions of young bodies. The wool is handed out in bundles of blanket-trousers-jacket-cap-socks, with a set of boots atop, by now perhaps already worn once by a pair of feet buried in a distant field.

It was autumn when the spores of the devil’s fingers left the beechwood of the island far away. It is autumn again, scarcely five months later, when they reach the beechwoods of France. Carried on the backs of humans, still nestled in the protective fibers of the wool, they are marched across the land. In time, the spores find their way back to the earth. Rain soaks the cloth and trickles the spores at last onto foreign soil. Caps and blankets and trousers are left behind, submerged in the sinking mud churned by thousands of feet. The stitched limbs of the uniforms, still encasing arms and legs, are blown and torn apart, landing in forgotten corners of trenches and fields, soon covered by mud. Fragments of bloody cloth are carried by shrapnel and embedded in the earth. Woolen blankets wrap legions of bodies, which are buried alongside the rows of trenches in mass graves. Over the course of the autumn, a few million spores trickle into the soil of the countryside.

In the meltwaters of the next spring, fingers emerge from the earth where the bodies were buried too shallow. This time, the underworld is real, covered by mere centimeters of soil. The surface of the earth bloats and distends. The stench of spoiled flesh is thicker than the fungi will ever recreate. The decay calls hordes of insects and animals to eat the rot from the soil, but the spore-laden wool remains. The flies swell to multitudes never before imagined. The fields hang thick with black clouds, the earth roils with maggots. In years to come the flies will be unable to sustain the numbers fed by this singular glut of decay. If flies had ancestors, if flies had legends, they would speak of the generation of that summer, and the year the earth burst in the bounty of rot.

But when the rot of bodies is over, when the soil is covered over with a fresh litter of fallen leaves, the spores of the devil’s fingers emerge from their hiding places in the thick fiber. Awakened by autumn rains they begin to branch out their little tendrils. White mycelium finds its way to beech leaves that taste different than the red beech a world away, the last common ancestors of the two diverging species separating with Gondwana. The leaves of the European beech fall more readily than their distant cousins on the other side of the world. The fungus now feasts on mats of decay. Leaves collect in thick carpets on the outskirts of the battlefields, and it takes the mycelium only a few years to crawl from the outskirts of the field to the forest that will be their new home.

The first egg-like sacs form in the wood. Pink tendrils burst forth into an alien world, gleba drips and coagulates along their unfurling lengths, the air is flavored with invasion. The fungi are greeted by the flies, the descendants of the greatest horde in living memory, whose ancestors knew all too well the stench of rot, the sight of fingers protruding from the earth.

Katharine Tyndall is a Berlin-based writer whose work has appeared in Nightmare, SAND, and many others. She is a 2025 finalist for the Grist Imagine 2200 Climate Fiction Prize. Her biggest hobby is identifying fungi in the woods; this piece was inspired by the carpets of invasive devil’s fingers in the forests near Cologne, Germany.

Published October 15 2025