The Primary Draw
Constanza Vergara pulled the access panel and counted the primary coils by touch.
Six. The readout on her slate said six. Her fingers said six. Tonight, six was the only number that mattered, because by shift end one of them would be missing from the Callisto Depot’s Cascade Reactor backup bank and the depot’s internal inventory would still read six.
The maintenance tunnel smelled like coolant and rust. A ventilation fan three meters overhead cycled on a bad bearing, the whine pitching up and down as the casing warped through its temperature curve. The sound had annoyed her for eighteen months. Tonight it kept her focused.
She braced a foot on the bulkhead and unseated the first coil’s retaining clamp. The coil was the length of her forearm and weighed twelve kilograms in Callisto’s feeble gravity. On Earth it would have crushed her wrist. Here she could lift it one-handed if she braced properly.
Six became five when the coil cleared the housing. She set it on the insulation pad beside her knee and began the swap.
The replacement coil had come in three days ago, folded inside a food-printer cartridge the way contraband always did now. The Iron Wake fence on Callisto moved components through food logistics because nobody cared to scan ration printers twice. The replacement looked identical to what she was removing. Same stamp. Same serial etch. Same alloy signature.
It was not identical.
The replacement had been pulled from a scrapped freighter, its internal lattice scored in fourteen places and its magnetic containment derated by thirty percent. It would hold under normal load. It would fail under any surge above the depot’s rated margin. Her schematic said the depot’s rated margin had not been tested in eleven years.
Her handler called it a parity swap. The reactor engineers would see six coils. The inventory would see six coils. The shielding calculation would see six coils. What the shielding calculation would not see was that one of those six would vent plasma through the backup bay if the primary ever tripped.
A coolant line above her hissed as it equalized. She flinched, then made herself breathe.
Constanza, report in on the hour.
The handler’s voice threaded through the bone-conduction patch behind her ear. She tapped the patch twice, the acknowledgement pulse.
Second coil is confirmed on the shopping list, the handler said. Pull two tonight. The buyer upgraded.
Her hand stopped above the second retaining clamp.
Two.
Two coils meant the backup bank dropped from six functional units to four functional units plus two scored replacements. The math on that she did not need a slate for. Four good coils would not carry the shielding load on a primary trip. The depot’s four hundred residents would have eleven minutes to reach pressure shelters before the coolant flare hit the habitat ring.
Eleven minutes was not enough time. Half of them slept on the ring’s outer quadrant.
She pressed the patch. “One was the deal.”
The deal is what it is tonight. The Ceres consortium doubled the order. Your cut doubles with it.
“One.”
Your brother’s Aurora packet ships Thursday. Funding clears against tonight’s pull.
The whine of the ventilation fan found a new note. Her brother Mateo had been working a refinery on Titan when his cascade reactor vented during a solar flare event. He had caught the Aurora Burn across his left cortex and down the spinal column. Three years of neural scarring had left him able to walk and unable to remember the name of anyone he met after lunch. The black-market med stream out of Ceres was the only supply of the cortical regulator his care-team could still obtain. The official allocation had been cut after the Defiant Stand rerouted most of the inner-system pharmaceutical production to frontline reconstitution.
One packet a month kept Mateo able to recognize her voice over a call. One packet a month was two thousand thermal credits. One coil tonight paid for four months.
Two coils tonight paid for nine.
She looked at the second retaining clamp. Her hand had not moved.
Constanza.
“The depot is four hundred people.”
The depot has never had a primary trip in its operational history. The probability is negligible.
“Probability is not zero.”
Your brother’s probability of remembering you by Christmas is not zero either. Let me know which zero you prefer.
She closed her eyes. The fan whine slid up the scale and back down.
The decommissioned bank on Level Four surfaced in her memory.
Callisto Depot had two backup banks. The one in front of her was the primary backup, rated for active load. The other was the secondary backup, a twelve-coil bank that had been decommissioned eight years ago when the depot shifted to single-redundancy architecture. Nobody had hauled the decommissioned coils out. Nobody had logged them. They sat in a sealed bay on Level Four behind a maintenance hatch that only appeared on a set of master schematics she had inherited from a reactor chief who had died of a pulmonary embolism two shifts before the audit rewrite.
The decommissioned bank was not in the current inventory. It was not in the shielding calculation. It was not in any operational document. On paper, it did not exist.
On paper, one of its coils could go missing without affecting the depot’s rated safety margin.
On paper.
She pressed the patch. “You get your second coil. It comes off Level Four. The one in front of me stays.”
Level Four?
“Decommissioned secondary. It is a clean pull.”
Silence. The ventilation fan cycled through two full oscillations before the handler answered.
If it is a clean pull, why did you not offer Level Four for the first coil?
Her jaw tightened. She had been testing herself, and she had failed the first test, and she had been saving the decommissioned bank for the moment she needed to feel like a person who still had a line somewhere.
“The first coil is done. I am telling you what I will do for the second.”
Understood. Pull the Level Four unit. Confirm on the hour.
She tapped acknowledgement.
The second retaining clamp lifted under her thumb with no resistance. She reseated it without removing the coil beneath. Six became six again in the primary backup bank. The scored replacement now sat in position one. The other five were still original.
Five good coils plus one bad one. The shielding margin would hold through any trip the depot had seen in its operational history. The probability was, the handler had said, negligible.
She closed the access panel and wiped her hands on a rag that smelled of coolant and cheap solvent.
Level Four was twenty minutes away through a maintenance crawl she had not entered in six months. She began walking.
Mateo would recognize her voice through Christmas. The depot would hold through any probable trip. A coil no living inventory had ever counted would cross to a private Ceres lab and teach a consortium metallurgist something he should not have been allowed to learn.
The math worked.
Her line had moved again. She tried to decide, as she walked, whether it had moved because she had chosen to move it or because the handler’s voice in her ear had kept finding smaller places to put it. The answer was the same either way, and it followed her down the ladder to Level Four.
Author’s Note: By Year 13, the fallout from the Defiant Stand had reshaped the outer-system economy in ways the reconstruction planners never modeled. Cascade Reactor primary coils, once stockpiled at every major depot, had become one of the quietest black-market commodities in the Jovian system, traded through food-logistics channels and pulled from decommissioned banks no official inventory tracked. The Iron Wake network on Callisto specialized in parity swaps, and the consortium metallurgists on Ceres paid extraordinary premiums for coils whose magnetic containment signatures could be studied outside UEN oversight. The line between keeping a family alive and keeping a depot safe moved more often than anyone in the reconstruction offices cared to admit.
If you enjoyed this story, you can follow the main story arc in The Exodus Rush, the first book in The Vethrak Requiem series.