Force Cantrithor by Michael McCloskey
Approx. 60,010 words.
Published on February 19, 2013.
When the alien enemies called the Vothriles ask for a secret meeting in deep space with Emil’s task force, everyone is suspicious. The warship Excalibur heads out to meet with the alien foes that no Terran yet understands. The Vothriles propose joining forces against an even greater common menace, a mysterious enemy code-named "Force Cantrithor".