What he ingested was so new the CDF didn't have a name for it yet, on a colony so new it also didn't have a name, merely an official designation: Colony 622, 47 Ursae Majoris. (The CDF continued to use Earth-based stellar designations for the same reason they continued to use a twenty-four-hour clock and a 365-day year: Because it was easiest to do it that way.) As a matter of standard operating procedure, new colonies transmit a daily compilation of all colony data into a skip drone, which then skips back to Phoenix so that the Colonial government can keep tabs on colony matters.
Colony 622 had sent drones since its landing six months earlier; aside from the usual arguments, snafus and scuffles that accompany any new colony founding, nothing of any note was reported, except for the fact that a local slime mold was gunking up damn near everything, popping up in machinery, computers, animal pens and even colony living quarters. A genetic analysis of the material was sent back to Phoenix with the request that someone create a fungicide that would get the mold literally out of the colonist's hair. Blank skip drones started arriving immediately after that, with no information uploaded from the colony.
Thomas and Susan were stationed on the Tucson, which was dispatched to investigate. The Tucson attempted to raise the colony from orbit; no luck. Visual targeting of the colony buildings showed no movement between buildings—no people, no animals, no nothing. The buildings themselves, however, didn't seem to be damaged. Thomas' platoon got the call for recon.
The colony was covered with goo, a coating of slime mold several centimeters thick in some places. It dripped off power lines and was all over the communication equipment. This was good news—there was now a possibility that the mold had simply overwhelmed the equipment's transmission ability. This momentary burst of optimism was brought to an abrupt halt when Thomas' squad got to the animal pens to find all of the livestock dead and deeply decomposed thanks to the industrious work of the mold. They found the colonists shortly thereafter, in much the same state. Nearly all of them (or what was left of them) were in or near their beds; the exceptions being families, who were often found in children's rooms or the hallways leading to them, and the members of the colony working the graveyard shift, who were found at or near their posts. Whatever hit, hit late and so fast that colonists simply didn't have time to react.
Thomas suggested taking one of the corpses to the colony's medical quarters; he could perform a quick autopsy that might give some insight into what had killed the colonists. His squad leader gave assent, and Thomas and a squadmate hunkered over one of the more intact bodies. Thomas grabbed under the arms and the squadmate took the legs. Thomas told his squadmate to lift on the count of three; he got to two when the slime mold rose up from the body and slapped him wetly on the face. He gasped in surprise; the slime mold slid into his mouth and down his throat.
The rest of Thomas' squad immediately cued their suits to provide faceplates, and not a moment too soon, since in a matter of seconds, slime mold leaped from every crack and crevice to attack. All over the colony, similar attacks were made nearly simultaneously. Six of Thomas' platoon mates also found themselves with a mouthful of slime mold.
Thomas tried to pull the slime mold out of his mouth, but it slid farther into his throat, blocking his airway, pushing into his lungs and down his esophagus into his stomach. Thomas sent via his BrainPal that his squadmates should take him to the medical quarters, where they might be able to suction enough of the mold out of his body to allow him to breathe again; the SmartBlood meant they would have almost fifteen minutes before Thomas began to suffer permanent brain damage. It was an excellent idea and probably would have worked, had not the slime mold begun to excrete concentrated digestive acids into Thomas' lungs, eating him from the inside while he was still alive. Thomas' lungs began to dissolve immediately; he was dead from shock and asphyxiation minutes later. The six other platoon mates joined in his fate, the fate that had, everyone later agreed, also befallen the colonists.
Thomas' platoon leader gave orders to leave Thomas and the other victims behind; the platoon retreated to the transport and made its way back to the Tucson. The transport was denied permission to dock. The platoon was led in, one by one, in hard vacuum to kill whatever mold was still lingering on their suits, and then subjected to an intense external and internal decontamination process that was every bit as painful as it sounds.