A Flag Full of Stars (Star Trek: The Lost Years #2) by Brad Ferguson

It has been eighteen months since the Starship Enterprise completed her historic five-year mission and her legendary crew has separated, taking new assignments that span the galaxy.

On Earth, Admiral James T. Kirk has married and started a new life as the Chief of Starfleet operations where he is overseeing the refit of his beloved ship, now commanded by a new Captain—Willard Decker. Kirk's only tie to his former crewmates is his Chief of Staff, a young Lieutenant Commander named Kevin Riley.

But Kirk's new, quiet life changes when he meets a scientist named G'dath who is on the brink of perhaps the greatest scientific discovery in a century. G'dath's invention could mean tremendous strides in Federation technology, or—in the wrong hands—the subjugation of countless worlds.

When Klingon agents capture this new technology, Admiral Kirk and Lt. Commander Riley are all that stands between peace and devastation for the entire Federation.