My Enemy, My Ally by Diane Duane is one of my personal favourites. You see, Star Trek's myriad amount of alien races is one of its most entertaining and memorable aspects. Of course, their individual traits and extremes only serve to highlight the same traits that can be found in humanity: the Klingon thirst for combat or the Romulan sense of duty and honour. Remember that TOS episode "The Enterprise Incident"? Kirk and Spock allow the Enterprise to be captured so that they can steal the Romulan cloaking device. The Romulan commander they encounter is noble, prideful and wholly dishonoured by Spock's attentions when their true purpose is discerned. After she is captured, she immediately adopts the shattered dignity of a captured prisoner of war. Diane Duane captures this theme in My Enemy, My Ally. When another female Romulan commander discovers a plot within the Empire that completely smacks of dishonour, she vows to defect from the Empire and alert the Federation to its existence. In order to preserve the honour of the Empire, Commander Ael t' Rlailiiu dishonours herself. The connection to the original series? She's the aunt of the other Romulan commander I mentioned earlier. Not only does Duane make a link to that previous storyline, but now she has invented another potential one for exploitation, and the story can continue.