Pocket Books released the final volumes in two series in a single month . . . though neither one is really a finale in that Star Trek New Earth: Challenger kicks off a New Frontier-type series centered on the Challenger crew, while Judith and Garfield Reeves-Stevens -- err, William Shatner -- promise that James T. Kirk will return following the end of Star Trek Preserver, which concludes the trilogy begun with Spectre and Dark Victory and succeeding the earlier Odyssey trilogy.

In the case of both Challenger and Preserver, it's rather helpful to have read the five books that precede each of them. Challenger is quite long and takes awhile to find its speed, unlike its New Earth predecessor Thin Air, one of the shortest and most dramatic of the miniseries' volumes. The latter is the sort of book you can't put down. Carey doesn't have as much energy in her writing style as Dean Wesley Smith and Kristine Kathryn Rusch, which works in her favor when her characters are being introspective of when she's describing people, but makes it a bit harder to get excited when she's introducing new characters, like in the first New Earth book.

Challenger starts with the man who's going to end up in charge of the new starship, Nick Keller, in the midst of a disaster that leaves him marooned, desperate get to the Enterprise as it fights a powerful enemy who represent a threat not only to Belle Terre, but to the enemies of the Federation colony there. Keller occasionally lapses into cliche, but for the most part he's a compelling character, cobbling a crew and ship together out of nothing, plotting mutiny and murder when he has to, killing a good friend to save others when he has to. Moreover, Carey brings back a wonderful character who "died" in the early pages of Wagon Train to the Stars for a critical role at the end.

The only problem is that, in this novel, these guys have to compete with Kirk and with dozens of compelling new characters introduced in this series. So while the plucky little wrestler who doesn't sound a thing like Starfleet can hold his own, Keller doesn't quite do the same. Peter David made MacKenzie Calhoun a boy hero, someone who came in with a legendary past despite his flaws. Keller's reasonably smart and tough and sensitive, but in this massive volume of a miniseries that has introduced many new characters and brought back many beloved old ones, he sometimes gets a little lost.

The same could never be said of Kirk in Preserver. The conclusion of the three-book saga concerning the alternate universe from the classic episode "Mirror, Mirror," Preserver focuses on a powerful alien race of Preservers who can create planets and possibly entire universes, though the Federation has doubts that they even exist. For anyone who needs the backstory, in Shatner's Odyssey trilogy, Kirk was revived after Generations by Borg nanotech and married a hybrid Klingon-Romulan named Teilani, who along with her unborn child is dying at the start of Preserver. She's been poisoned. Kirk makes an alliance with Emperor Tiberius, formerly of the ISS Enterprise, to save her life.

Unfortunately, at the time Kirk makes this unholy pact, he doesn't yet know that Tiberius will be repsonsible for the end of the universe if something isn't done. The story brings in threads of dozens of original Trek episodes, from Miri's world to Balok to the Guardian of Forever (which has surprising links to the storyline). Despite the fact that he is well over 100 years old, McCoy assists Kirk along with Spock, while Jean-Luc Picard and the crew of his younger Enterprise try to sort out what's at stake.

Don't be fooled into thinking this is another Kirk-Picard collaboration, however. This is a Kirk book through and through, which I mean in the best possible sense. It's packed with action, potshots at the Prime Directive, angst about the captain's obligations to his crew, Starfleet, and the civilians of the galaxy, and speculation about the nature of parallel universes and parallel personality counterparts. Shatner and the Reeves-Stevenses know all these characters and the affection shows through. Even when Kirk is behaving like a jerk, it's impossible not to feel for him.

That's the uncanny thing Peter David somehow managed in New Frontier, to create a captain who's funny and flawed and brilliant and passionate and absolutely real even though he's larger than life. Carey hasn't quite managed it in Challenger, but this is only our introduction; there's a lot of room to grow.