Captain Vorpatril's alliance

“Our current best guess of what existed in between the two ends prior to the bomb blast.” Dotted yellow outlines, branching and re‑branching directly under the ImpSec subbasements.

“The Mycoborer walls appear to cure very hard, strong in compression but weak in tension, and brittle. At some point during the firefight between the criminals and the ImpSec guards who pursued them underground, someone’s stray stunner beam struck the old bomb on the tunnel floor, setting it off.” Scrupulously, Otto’s picture did not suggest whose stunner this triggering energy pulse came from. A flare of purple light filled the tunnel network. “The air and gasses in the tunnels transmitted a strong concussion to the walls throughout; we don’t yet know if there was further chemical reaction. The stretching in tension cracked and in some places shattered the walls, both visible and micro cracks. At the same time, the weak portion of the storm sewer abutting or closely abutting the Mycoborer tunnel blew out, a section of the drain just down from the breach collapsed, the water so dammed diverted through the breach, and the shattered tunnel began to rapidly fill. Water not being compressible, this actually helped keep the network from collapsing for quite some time. Water from the on‑going heavy rain drainage further penetrated and weakened the cracked walls, and began mixing under considerable pressure with the formerly dry and solid subsoil. In effect, the branching Mycoborer tunnel turned into a giant sponge under the ImpSec Headquarters.” A bulky, irregular region under the green cage filled with red light. “The pressure mounted.” The red light grew more intense; the sponge swelled.

Both Illyan and Allegre had exactly the same expressions of horrified fascination on their faces, Ivan noted in a brief look around.

“At the time that my engineers dug down to the bunker roof with grav‑lifters”‑a white circle appeared on the ground level of the park, and grew downward to the blue box in a neat cone‑“possibly at the moment that we cut through the roof, the storm sewer unplugged itself. I suspect, but can’t prove yet, that the vibrations from our rescue work might have helped that along. In any case, the sewer unplugged and began draining the Mycoborer tunnel network of what was now a hell of a lot of liquid mud. The ImpSec building directly above acted as a giant weight, compressing the sponge and expressing its contents out the newly opened exit channel.”

Pulses of red light marched down the storm sewer.

“And the rest”‑Otto sighed‑“we all witnessed.” Slowly, as the red sponge flattened, its filaments collapsing, the green cage began to sink below the brown ground lines.

“How far down d’you think we’ll end up?” asked General Allegre, from his back row.

“Not much farther, I think. A man should just about be able to jump off the roof to the ground. Without breaking his legs, that is.”

A little silence followed this word‑picture. If Allegre contemplated suicide over all of this, he was going to have to find another method than the traditional parapet, Ivan reflected. Gregor stirred himself and broke the hypnotized hush with, “Thank you, Colonel Otto, that was very clear.”

“Thank you, sire. But the big question I want answered”‑he pointed to the sewer line‑“we know damned well that bits of Mycoborer tunnel walls had to have been mixed with the mud. Which has mostly ended up in the river. What’s it doing downstream?” His glare at the Arquas was impartial, but far from impassive.

“For the answer to that question, I hope Dr. Weddell will have more information than this time yesterday. Doctor?” At Gregor’s gesture, Otto stood down and Weddell took his place.

Weddell was a distinguished‑looking researcher in his sixties. His past, Ivan had reason to know, was considerably more speckled than his appearance would suggest, but that didn’t make him less able to do his job. Possibly the reverse.

Weddell cleared his throat, nervously. “Well, sire. As we all know, absence of evidence is not evidence of absence. Nevertheless, my field teams have not yet found live Mycoborer cells downstream from the capital. We have, on the other hand, positively identified a few fragments of former tunnel wall, and if the one is present the other should be, too. One bright spot‑the live cells we’ve been studying do not appear to like an environment of salt water. So if any reach the sea, it is unlikely they will survive there.”

“Told you that,” murmured Lady ghem Estif. “Three days ago.” Weddell gave her a rather driven look.

“While I do strongly recommend we continue to monitor, it is my opinion that the Mycoborer is less a hazard than several other biological nightmares you Barrayarans have lived with for years, not excepting this planet’s own native ecosystem. Prudence yes, panic no. Add it to the list and go on, I’d say.”

Tej, listening intently, blinked. “Hey,” she whispered to Ivan. “That fellow’s a Jacksonian. Or he was.”