Swarm ? What swarm ?

From: hcarteau_at_3hY2FgXTrOCU39De9Z50o52Ky-H12v-YDOkSh6t7MbRXi8raExI3EHKo_20rt9w9PRW
Date: Tue, 19 Jul 2011 14:31:58 +0200

Selon Jeff <richaje_at_7inEz4CMhxs-Tjcf89r4ruq-VS5L6G3bP6r6pYoM7oRsW9oeqsK5-sqrlOnOa2pVcjlNZp8S8unb.yahoo.invalid>:

A MAJOR event of the early Hero Wars is trolls bringing various pieces of Kyger Liter and her daughter (among other things) back to the Castle of Lead in Dagori Inkarth.
The most notable of these is an event called The Swarm by humans, and brings darkness and terror to the peoples of Ralios, South Peloria, Dragon Pass and beyond.

/// One wonders : what is this "swarm" made of, praytell ?