The sequel to Into the Looking Glass takes up the story more than ten years later. The US is launching its first starship, based on a nuclear submarine and and alien propulsion system. The novel follows the mission. It is an escalation of encounters from very mild to extremely deadly, with quantum physics sprinkled throughout.
Unlike Into the Looking Glass, which I was somewhat disappointed with, I thoroughly enjoyed Vorpal Blade. It is a fun romp with the right doses of humor and action. The characters are engaging, fun and well-written. You really get a sense of being with them on the starship. Fun!