The latest crisis facing Earth: an invasion of Zahurians, a race of telepathic and highly mobile alien trees that kill and devour almost any flesh-and-blood organism in their path, can't be negotiated with, and are consequently hated by most sapient races in the galaxy. When a group of 208 are dropped off on Earth to feed, it's up to the Men In Black — primarily Jay and Elle, along with their containment team JE (JayEe), KB (K'Bee) and RL (R'Elle), known as "Pro", "Captain" and "Partner" to their friends — to hunt down and destroy the Zahurians before other aliens arrive to hunt the trees down themselves, which could prove a containment nightmare.
This book contains examples of:
- Arc Number: Brought up repeatedly throughout the book — a healthy Zahurian adult has 208 branches, making 208 a sacred number to their kind. Consequently, when Zahurians are transported to another planet to feed, it's in a group of 208 at a time (though when they come to Earth, they're typically dropped off in smaller batches, some distance away from one another). The Men in Black aren't aware of the exact significance (due to the Zahurians seeing all non-Zahurians as food only and being unwilling to communicate with them as a result), just that 208 is important to the Zahurians somehow.
- Hated by All: The Zahurians, a race of Plant Aliens that look like trees and devour almost any flesh-based species (with the exceptions of those that they use for pollination or transport across the galaxy, or that make them sick if eaten) in their path. A number of races have something personal against them, and come to Earth with the intention of destroying the batch that's recently arrived, forcing the MiB to repel them while trying to hunt down and destroy all the Zahurian invaders.
- Hidden in Plain Sight: Late in the book, after their telepathic "ally" has been killed, Jay and Elle have to figure out where the last sixteen Zahurians are hiding. Jay comes to the sudden realization that they don't need to be looking for trees — they need to be looking for hiding places, where the tree-like aliens could blend in without being spotted. Later on, a comment from the waitress leads them further along the right path, to finding places where a lot of flowering plum trees could sit around without being seen as out of the ordinary. The agents ultimately find the Zahurians in a local mall, one already heavily populated by mundane flowering plum trees.
- Horde of Alien Locusts: The Zahurians, one of the most hated species in the galaxy. They look like flowering plum trees, but they're dropped off in groups of 208 and see most other species only as food, devouring any living beast or being they can (though the group in this book is more careful about picking their targets because they don't want to get caught) and refusing to communicate with them, save for about three species — one serves to pollinate the Zahurians, a second has a chemical in its bloodstream that makes the Zahurians sick, and a third is willing to transport them to other planets to feed there.
- Improvised Weapon: The Zahurians typically rely on a Deadly Disc, which they call a Cutting Disk (with a sharpened edge), as their weapon of choice from a young age. None were brought on this trip to Earth, but one of the Zahurians finds a substitute in the mall where they're hiding out — normal Earth plates, which actually drive away the MiB agents with their first salvo. The Zahurians aren't so lucky the second time though.
- Kill It with Fire: The preferred method of dealing with the Zahurians. Specifically, when facing a large group of them, Jay breaks out the same massive Phaser rife that he'd used to shoot down Edgar's ship in the movie, switches it to a wide beam (which is explicitly compared to a flamethrower, but with an invisible beam that's so hot it melts almost anything it touches) and torches the Zahurians and any and all plantlife around them.
- Man-Eating Plant: The antagonists of the book are the Zahurians, a race of mobile Plant Aliens, which resemble flowering plum trees and will slice, dice and suck up (through their roots) the remains of any fleshy beast or being they can reach. Naturally, this trait (combined with their refusal to communicate, and thus negotiate, with their would-be prey) makes them one of the most hated races in the galaxy.
- People Puppets: Downplayed — the Nelek are a race of telepaths, who can mentally seize control of and paralyze other species. Zed is not happy when he learns the Nelek he'd reluctantly recruited had used their abilities to paralyze Jay and Elle so the alien could be free to devour a pair of Zahurians the group was hunting; fortunately, his attention being divided meant the two agents were able to break free and kill all three aliens.
- Read the Freaking Manual: "Jay" refuses to read the manual. Any manual, whether it be on the customs and etiquette of the species they plan to contact or a weapons manual. "Elle", who has read the freaking manual, shows him how to use the Noisy Cricket without the recoil. A probable parody, as it is lampshaded that she only knew this information from the manual, the manual was written in an alien language, and it would have shattered her wrist and probably shoulder had she been at all wrong.
- Revenge Before Reason: The norm when it comes to most races and the Zahurians. They don't care that Earth's MiB are already hunting down and killing the Zahurians, they want revenge for that race killing one (or more) of their own and want to deal it out personally.
- Sapient Eat Sapient: The Zahurians are a race of Man-Eating Plant Aliens who devour non-plant species regardless of sapience (and sometimes even other plants too, out of desperation), which makes them one of the most hated species in the galaxy. The tables are turned when the MiB recruit a Nelek, a member of a telepathic alien species, who is revealed to be capable of paralyzing and eating the Zahurians (and is most annoyed when the MiB agents burn them before he gets the chance to feed).
- When Trees Attack: The plot involves the Zahurians, tree-based aliens that vacation on Earth and feed on just about any flesh-based life form, slicing up the creature (or person) with their roots and absorbing everything. Amusingly enough, the light from the Earth's sun is dangerous to them, as it eventually turns them into real trees (plum trees!).
