"the summons rings were part of a pact that the four friends--Wren, Tyron, Teressa, and Connor--had made last year, after the troubles besetting the kingdom had begun in earnest."

Wren's War - Sherwood Smith

This book was so much better than the second. The character's really grow, not only in ways that change their lives forever but ways that also make their friendships different. It was well worth reading!