An electro bio-mechanical neural transmitting zero synapse repositioner, commonly referred to as a neuralyzer is a top secret device used by the MiB. It has the ability to wipe the mind of anybody who sees the flash.

Following the film's release, Ray-Ban stated sales of their Predator 2 sunglasses (worn by the organization to deflect neuralyzers) tripled to $5 million.

After an almost-botched operation to arrest an alien criminal named Mikey near the Mexican border, Agent D decides that he is too old for the job, prompting Agent K to neuralyze him so he can retire.

NYPD officer James Darrell Edwards III pursues an unnaturally fast and agile suspect into the Solomon R. Guggenheim Museum. Impressed, K interviews James about his encounter, then neuralyzes him and leaves him a business card with an address. Edwards goes to the address and undergoes a series of tests, for which he finds unorthodox solutions, and K offers him a position with the MIB.

Jeebs deals in stolen objects, both alien and human. When K grows impatient with Jeebs, he blows his head off. Fortunately, Jeebs has the ability to grow it back.

After the crash, an aggressive cockroach-like alien kills Edgar and uses his skin as a disguise.

Tasked with finding a device called "The Galaxy", the Edgar alien goes into a New York restaurant and finds two aliens (disguised as humans) who are supposed to have it in their possession. He kills them and takes a container from them but is angered to find only diamonds inside.

After learning about the incident in a tabloid magazine, K and J investigate the crash and head to a morgue to examine the bodies the bug killed.

Inside one body (which turns out to be a piloted robot) they discover a dying Arquillian, who says that "to prevent war, the galaxy is on Orion's belt". The alien, who used the name Rosenberg, was a member of the Arquillian royal family, and K fears his death may spark a war.

J deduces that the galaxy is hanging on the collar of Rosenberg's cat, Orion, which refuses to leave the body at the morgue. J and K arrive just as the bug takes the galaxy and kidnaps the coroner, Laurel Weaver.