Most fans will probably like The Genesis Wave duology because it's filled with action, introduces a bizarre and deadly alien, and seamlessly weaves together plot points from the original Star Trek and The Next Generation. I loved it because it brings back Carol Marcus, one of the finest female characters from Classic Trek, and Leah Brahms, one of the most intriguing women from The Next Generation, putting them at the center of a fantastic adventure story along with Admiral Nechayev and a specialist named Dolores Linton.

In the waning days of Voyager, with Captain Janeway's sputtering command and Seven of Nine's catsuited conceit as our primary female role models, it's especially heartening to see so many wonderful women with rich, complex lives and careers. John Vornholt is one of the few Pocket Books Trek writers who seems to have an equal grasp on characters from all four televised Trek shows, as he proved in the Gemworld two-parter, The Dominion War series, and his installment of Double Helix. In The Genesis Wave, he puts the matter-rearranging technology from The Wrath of Khan to surprising use, bringing in two characters from that movie and The Search for Spock to join with the Next Generation crew in saving Earth.

The first volume witnessed the kidnapping of Dr. Marcus, who had been in seclusion to keep Genesis safe from potential enemies. Once she unwittingly helped unleash it in a wave across the quadrant, it took the life of the husband of Dr. Leah Brahms, Geordi LaForge's unattainable love from "Galaxy's Child." Brahms, in turn, joined with aging Klingon Maltz -- survivor of Captain Kruge's vessel, commandeered by Kirk -- on a personal quest for revenge. They want to protect the galaxy, but they all have compelling personal and professional reasons for their involvement as well.

The Genesis Wave, Book Two begins with the successful salvation of the population of Myrmidon, a world inhabited mostly by Bolians, including the Enterprise's Mot. But Admiral Necheyev has been critically wounded, leaving Geordi LaForge to try to prevent chaos on a gruesomely transformed planet with panic-stricken citizens. To make matters worse, the strange new plants growing in the wake of the Genesis Wave seem to be causing hallucinations of the sort that made Carol Marcus believe her son David was still alive while she perfected the wave.

Picard seeks Romulan allies, who are willing to help save Earth, but the price may be letting this long-term enemy gain access to Genesis' deadly secrets. Meanwhile, Brahms and Maltz take a Klingon crew in search of the perpetrators of the Genesis Wave. They soon learn that the unseen enemy hasn't been terraforming the planets to prepare for a later invasion, as they had assumed; the invasion has already taken place, built into the new Genesis matrix and spreading rapidly over Myrmidon and all other planets touched by the wave.

Most of the major characters shine in this sequel, particularly LaForge, who plays an even bigger role than Picard in facing the menace. Even as he frets over his inability to make his passionate feelings known to Leah Brahms, LaForge develops a strong connection to warm, witty Linton, who treats him more like an equal and makes the reader start to hope he'll rethink his romantic priorities. Brahms, whom we've seen thus far primarily as an engineer, proves to be an able commander and a decent strategist as well. Faced with odds that seem impossible, she manages to gather the information that stops the threat at the source.

This is a novel full of heroes, where minor crewmembers like Mot and Linton perform acts of bravery as important as those of Admiral Nechayev. The admiral rushes back to work following a near-fatal injury to try to stop the wave, only to learn that her efforts may have been meaningless. Crusher recovers from a bout of possession by invasive fungus to study its effect on humanoids. Troi -- so often sidelined because her empathy leaves her weak in the face of widespread suffering -- is the only crewmember sensitive enough to the invaders to stop them aboard the Enterprise.

Mind-controlling fungus may sound like a menace more appropriate to campy horror films than Star Trek, but as Vornholt describes it, it's genuinely creepy and oddly sympathetic. The Genesis Wave itself becomes a bit more removed as a threat once Starfleet realizes it can save the people if not the planets using interphase generators. Once the mutagenic matrix has been neutralized, the focus shifts to finding those responsible for unleashing the graphically dramatized destruction.

My one plot quibble stems from the fact that I was never entirely clear how the fungus learned of the capabilities of Genesis, nor how Starfleet security allowed them to track down the carefully guarded, asocial Marcus. I would have enjoyed learning a little bit more about the science -- the device has been much refined since The Search For Spock, able to modify suns for target planets and to control the evolution of all life in its wake.

There's something in these novels for most Trek fans -- Klingons and Romulans, original and Next Gen characters, action and romance, tragic deaths and breathtaking salvation. At the end of The Genesis Wave, Book Two, everyone believes the knowledge necessary to recreate the matrix has been lost. But of course Starfleet isn't willing to commit genocide against the fungus, and the transformed worlds remain Genesis planets, far more stable than the one in The Search For Spock and undoubtedly containing evidence of their origins.

Vornholt leaves ample opportunity to revive Genesis again, on a small scale as in The Wrath of Khan or on a grand scale to make hunks of rock livable. As he keeps pointing out, Genesis has amazing capabilities as a dramatic device as well as a terraforming agent; because it makes changes at the subatomic level, it could be used for cellular regeneration, offering eternal life or constant revival like Spock experienced in the films. The immediate threat has been averted in The Genesis Wave, Book Two; now it would be fascinating to read a sequel in which this life-giving force is used purely for positive ends, with the usual hazards of playing god factored in.