Stone and Anvil

Now at last, Captain Mackenzie Calhoun and Captain Elizabeth Shelby return in a page-turner that explores the past of both captains - while simultaneously confronting them with a perilous dilemma in the present.
A crewman has been murdered aboard the U.S.S. Trident, and all evidence points to Ensign Janos of the Excalibur. Calhoun is reluctant to accept that Janos, a powerful non-humanoid whom the captain has known and trusted for years, could be a killer and immediately launches an investigation into the crime. But this troubling murder mystery soon escalates into a full-fledged diplomatic crisis that threatens to pit Calhoun and Shelby against the entire United Federation of Planets - and the Starship Enterprise.
Meanwhile, the turmoil involving Ensign Janos forces Calhoun to recall his own tempestuous past, his rocky relationship with a young Elizabeth Shelby, and a long-ago exploit that may have everything to do with the deadly emergency that now confronts them all.