The region of Isk where Altarrin's mine was placed is in the tundra, the kind where meltwater pools and mosses and ground-plants flower during a brief summer, but the underlying permafrost never thaws. It's not quite perfectly flat; there are ponds and hillocks and even low, flattened rolling hills, but there are no trees. Nothing to break the northern horizon, all the way to the Icepack sea, where icebergs drift past even at the height of summer, when the sun processes around the horizon more than it exactly rises and sets, and for a time there is no night at all.
The summer is over - there's frost at night already, and rimes of ice on the pools, despite the fact that further south the harvest has yet to arrive. It's not yet winter, those endless months of darkness, but they days are quickly shortening, and the wind at night is bitter.
The mine is not much inconvenienced by the weather. It was built in stages, starting with an open excavated pit, carved out the sod well below the permafrost line and all the way down to bedrock, drained and sealed and then neatly sheltered from the elements by a permanent weather-barrier; all further work was done once that was in place. The dome covers the small on-site administrative office in a blocky sod-and-brick building, some utilitarian roofed but open-sided storage shacks, some equipment for ore-sorting and processing before the semi-purified results are Gated to a centralized metallurgy facility (based somewhere less miserably cold). There is, or rather was, an additional gazebo-like shelter over the primary mine-shaft, which drives down through five hundred feet of bedrock. (Though the deepest parts don't, yet, have any side tunnels.) The sleeping quarters for the mine staff, about fifty people (eight mages) were also underground, though not dug in nearly as deeply.
From underground, it's easier to use detection spells to hone the initial survey results, and make further decisions on which ways to excavate. Even barely a month in, there were over a thousand feet of reinforced tunnels, measured horizontally. (Thirty deaths; node-energy is sparse up here, and thirty is actually somewhat below the standard allocation for a project of this scale. When and where to use blood-power was a call made by the administrative project manager and the lead mage-engineer, according to centuries-old protocols.)
The area has a very productive seam of iron, probably the main finding that caused the Empire's surveyors to mark it down as a potential future site – but it does also have an area with rich ore deposits of a new metal, one that apparently has magical properties that interact with a rare Wild Gift.
That section is where things went wrong.
It doesn't look awful, from the outside. The artifact powering the permanent weather-barrier is down; there appears to be a temporary mage-barrier replacing it, which is not very successfully keeping in the heat; there's a barrel of water outside the administrative building, whether for drinking or washing is hard to tell, and it has a skin of ice.
Documentation - copied to offsite - includes a rash of accidents dating back a week. Weird accidents, both of the 'could well be sabotage' kind, and the kind that definitely couldn't have been done on purpose but are still suspicious and implausible. Debriefs and questioning the mine workers and swapping around shift schedules to break up a possible conspiracy all failed to halt the pattern.
Altarrin, for some reason, traveled north in person - one communication-spell-relay report claims that he mentioned casually it was 'on his way', but this makes less than total sense given that his previous assignment was in the far south, and Gate-cost scales with distance, albeit less so when one is using the permanent Gate-network and, like the Archmage-General, has the authorization level to go from any point direct to any other point if both are on the main network, rather than needing to route through a centralized nexus (staffed by mages to check compulsions and cargo or baggage, and with randomly-determined Thoughtsenser coverage.)
Altarrin looked at personnel records, and asked for three particular staff to be detained and questioned, on suspicion of being agents for Vkandis. He did not have a Thoughtsenser with him, at the time, but delegated the task to a mage who should have been more than capable of it, and didn't venture into the mine itself to inspect the scene until it (should have been) entirely evacuated. The time would have been two candlemarks before noon – not long after dawn, on these short days.
There is a gap in their records of several candlemarks, when Altarrin's mage-secretary was only passing occasional and un-detailed status reports; the communication spell is tiring from deep underground. They have no particular indication that something was going wrong, but they don't have much information at all.
At twelve minutes past noon, a routine guard-sweep found the mage sent to interrogate the prisoners unconscious, and both his clerk and the prisoners themselves missing.
A message was passed urgently to Altarrin's mage-secretary, who at sixteen minutes past noon provided a report that - seems to have gotten rather garbled in the transcription. It seems like there was...maybe a problem...? The secretary requested "non-urgent backup" and a Healer. What exactly the problem was, did not make it into the record.
"Non-urgent" or not, the mine administrative manager reacted quickly; the site on-call Healer was sent down immediately along with the rest of Altarrin's personally-loyal mages.
No further reports would be received from Altarrin or his crew.
At twenty-one minutes past noon, there was a violent underground explosion - maybe a Final Strike, maybe an artifact, maybe not magical at all and just the result of one of those underground gas-pockets, though the surveyors hadn't suspected one. Impossible to tell without going underground to inspect the ruins for a close-up magical signature.
The casualties, once tallied up, were actually less bad than feared. Altarrin, obviously. The assistant mage-engineer who had gone down to show Altarrin some of the accident sites, Altarrin's secretary and the mage-engineer's clerk. Five of Altarrin's mage-entourage. The Healer, unfortunately. But everyone else was on the surface, or under guard in the separately-dug-out barracks, and injuries were relatively minor.
The blast took out the weather-barrier dome and mage-lighting, which was not ideal for coordinating a response, and damaged the Gate; it was ten minutes before the lead mage-engineer could repair it enough to send someone out with a report and an urgent request for a replacement Healer please.
The site was too hot to check for survivors (or, more realistically, count the bodies), and by then the mine leadership had already received instructions to not touch anything, hold all mine personnel in their barracks under political prisoner-grade compulsions, and wait for the experts to come untangle this mess.
