Thirty books, some the kind you could pick up in your local library, others that are carefully hidden away from the general public for good reasons.
30 books to be found within a steampunk setting. Manuals, tomes, and blueprints galore!
The PCs traveling along the road/path/trail begin to hear a low droning sound. As they approach they find their path obstructed by hundred of thousands of droning insects. Locusts swarm though the air, feasting on the grass and plants. Passage will be slowed, but the insects pose no threat to the party, aside from being crunchy and disgusting underfoot, climbing into pouches and eating exposed food goods.