Book one of this series, Worf's First Adventure, focused on the feud between Worf—the first Klingon in Starfleet Academy history—and Zak Kebron, a member of the Brikar race known for their hatred of Klingons. Worf and Zak were constantly on the brink of physical confrontation, but by the time Line of Fire starts they have come to tolerate each other, perhaps even be friends. They and three other first-year Starfleet cadets—Soleta the Vulcan, and humans Tania Tobias and Mark McHenry—have formed a study group that's so efficient they are called the "Dream Team" by professors and cadets. Presently, Professor Alexander Trump calls the Dream Team into his office and requests they head up an expedition to Dantar IV, a planet co-colonized by the Klingon Empire and the United Federation of Planets. Dantar IV is quickly descending into interracial disharmony, but Professor Trump believes the Dream Team can help. Worf will be their secret weapon; a Klingon raised by humans, if anyone can bridge the communication gap it would be him. Worf isn't happy to be chosen for the mission based on his race, but he agrees to accompany Trump and the other Dream Team members.
Blistering hot weather engulfs the cadets as soon as they teleport from their ship to Dantar IV. Federation administrator Paul Dini welcomes them and Professor Trump to the planet and introduces them to Klingon administrator Khard, who has brought three younger Klingons to Dantar IV to help improve communication between the races. Gowr, Kodash, and K'Ehleyr are taken aback to see a Klingon like Worf in a Starfleet uniform, and Worf is equally affected by the sight of his first female Klingon, K'Ehleyr. Displaying the problem-solving intelligence that got him into Starfleet Academy in the first place, Worf sets to work finding solutions to the grievances between the Federation and Klingon colonists. His success rate is impressive; tensions disappear, and the Dream Team will soon be able to head back to Earth.
Gowr, Kodash, and K'Ehleyr's judgmental stares are unnerving to Worf. They seem to regard him as either a social freak or moral coward, but there's no denying his excellent work on Dantar IV; Worf's understanding of both human and Klingon custom uniquely positions him to ease unrest in the colony. However, someone lurking just beyond planetary orbit has no intention of letting him succeed. Launching a surprise attack, an anonymous Klingon vessel reduces much of Dantar IV to rubble, causing Worf flashbacks to the massacre that killed his own parents when he was six years old. The Dream Team must repair Dantar IV's damaged phaser cannons to prepare for a return of the Klingon hostiles, or everyone on the planet will be incinerated. Can Worf and his friends prove their mettle as Starfleet cadets by surviving this disaster?
The mixture of races on Dantar IV has been volatile from day one. Avoiding violence in such a scenario requires a cool head and willingness to empathize with people you may have nothing but contempt for. These aren't Worf's natural strengths, but he enrolled in Starfleet Academy to make the most of his life, and doing so routinely takes him out of his comfort zone. This is the case even when dealing with the human members of the Dream Team. "He was aware that there were subtleties to human emotions that he was not yet grasping, indeed, perhaps would never grasp. But to remain stubborn in all matters until he did understand them—whenever that time might come—would leave behind him a long road of hurt emotions and feelings. That was no way to live." Frustrating as it often is, Worf wants to be a voice of conciliation between the Federation, Klingons, and whatever unknown alien forms may wait in deep space, and his determination will go a long way toward that goal.
Line of Fire is a small step down from Worf's First Adventure, in part because it lacks a true ending. It just trails off into Survival, the final book of this trilogy that kicks off the longer Starfleet Academy series. I expect Survival will answer lingering questions from this book, such as why the Klingon invaders targeted Dantar IV. I appreciate the inclusion of a character named Paul Dini in Line of Fire, presumably to honor the comic book writer of the same name. I was also amused by mention of the grain quadrotriticale, a subtle reference to "The Trouble With Tribbles", probably the most iconic episode of the original Star Trek television series. These first two Starfleet Academy books haven't been riveting, but they're a nice diversion for Star Trek: The Next Generation fans, and I look forward to volume three.