How are the PCs involved?
From Spiders
For some reason, the other Sidereals aren't really helping much. It's the PCs solving this. Why?
Are the other Sidereals too busy holding ground, so only the PCs solve the problems? E.g. if the Spiders rebel, the other 95 Siderials are busy weaving the loom by hand (or forcing the spiders to).
Perhaps the Maidens appeared to make grand speeches explaining that they're going away for a while and everything's planned... whether that's really them or not is in question, but 95 of the 100 buy it.
Perhaps the other Siderials are corrupted or mislead in some way and can't be trusted.
Perhaps the PCs have the unique maguffins, embedded in their shards.
Perhaps the PCs are just one of many teams dealing with small problems, and are lucky to find the real problem.