Captain Kirk and his crew (minus Spock, who is on leave) are assigned to a rather routine mission: transporting diplomats in the middle of tough negotiations. Things get tricky when one of the wives of the party is Kirk's old girlfriend - who would like nothing better than to renew the acquaintance (wink wink) -, while another diplomat insists on gifting Kirk three wives. Just when things couldn't get more awkward, an attache is murdered and the prime suspect is one of Kirk's own crew.
A rather dull outing, lightened with occasional humor, but most of the action is focused on a unusually dithering Kirk, confounded by the rather simple murder situation. This might be explained by the fact that the book was originally written during the Enterprise first five year mission and was rewritten to be set after the first movie, but a weak plot is still a weak plot. The answer to the mystery is so obvious, especially to a crew with the Enterprise's experience, that I found myself shouting, "It's a blood shape shifter, you meatheads! Not like you haven't seen that before!" and wishing that Mr. Spock would just come back already.
Summary: Weak plot, poorly constructed mystery, but good prose. If you'd only time for one quick read, skip this and go for Prime Directive or Yesterday's Son.
Character ratings: Voices (inflections, etc) all Bs. Actions and motivations, all Cs.