Note: Cover says this is Book 1 of The Elfin Trilogy, but the only other book by Wanzer on WorldCat is Smoke on the Horizon, also published by Commonwealth a year earlier. The 1 library that owns a copy does title it Smoke on the Horizon but lists the same ISBN as The Elfin Brood, and there is no mention of Smoke on the Horizon online, so it's likely that was the working title and it was published as The Elfin Brood.