Christmas episodes of television are a dime a dozen, but Halloween episodes are a rarer beast. That’s why it’s especially notable that Millennium, Chris Carter’s criminally underrated series about profiler Frank Black (Lance Henriksen), had two during its brief three year run.

“…Thirteen Years Later” (1998) is a fun riff on the horror genre. “The Curse of Frank Black” (1997) is nothing short of transcendent.

“Curse” was written by Glen Morgan and James Wong, who took over showrunning Millennium when Carter became busy with The X-Files movie and fourth season. Morgan and Wong, who would go on to help create the Final Destination franchise, brought a fresh perspective to Millennium following its relentlessly dark, serial killer heavy first season. The entire season, much of it personally written by the duo, holds together incredibly well over two decades later, and “The Curse of Frank Black” is certainly no exception.

The installment concerns Frank (always vividly portrayed by Henriksen) who experiences a dark night of the soul on Halloween. Confronted literally and figuratively by the ghosts of his past, Frank conveys a multitude of emotions with a largely wordless performance. (Damn, but Henriksen is a terrific actor.) The episode is not only the best of the entire series, it’s one of the most mesmerizing hours of television I’ve ever seen. Less plot driven than a moody tone poem full of indelible Halloween imagery (and windy, ominous sound design), “The Curse of Frank Black” is both a great Halloween episode and much more.

The evening begins normally enough, at least by Frank’s standards. On a night off from detective work, he takes Jordan (Brittany Tiplady), his daughter with estranged wife Catherine, out for trick or treating. A cold open reveals that the jack-‘o-lantern he’s carved before leaving the house has relit itself. Soon, more strange events occur. Jordan, who seems to have inherited Frank’s second sight, refuses to go to a house she has a bad feeling about. Frank glimpses an eerie winged devil in the upstairs window of the same house (the most vivid image in an episode full of them). In his car, Frank’s Bobby Darin CD refuses to play, but Screamin’ Jay Hawkins’ gleefully ghoulish “Little Demon” keeps sounding over the radio.

Frank winds up at his old house, where neither he nor his family live following his separation from Catherine. He finds a group of teens in the basement telling a ghost story—about him and his dark, violent past. (In the premiere, Frank brutally killed a serial killer who threatened his family in the same basement.)

At his new apartment, Frank is bombarded by the number “268,” and realizes he’s been seeing the numbers all night long. They lead him to Acts of the Apostles Chapter 26, Verse 8: “why should it be thought incredible by you that God raises the dead?” In fact, the dead do appear to Frank, in the form of Crocell (Dean Winters), a depressed WWII veteran Frank met as a child on Halloween many years earlier. We see their first meeting in a gorgeous, black and white flashback in which Crocell discusses the holiday’s connection to death and his frustrated desire to see his fallen comrades. Now, he warns Frank that if he continues on his current path fighting the forces of darkness, it will result in grave consequences for him and his family.

In the light of day, Frank feels much more optimistic—but Halloween’s eerie spell lingers in the audience’s mind.

The episode has a lush, shadowy look and feel that perfectly evoke Halloween, aided by “Little Demon” and a particularly strong score by Mark Snow. The smallest touches add to the haunting effect; there’s a wonderfully creepy bit with Frank’s TV and a laughing, animated Devil (taken from an obscure 1933 film called The Mascot). It’s such a great episode that it’s little surprise that the next Halloween installment, “…Thirteen Years Later,” pales in comparison.

But it’s still an inventive hour that’s particularly fun for horror fans.

The story centers on the production of Madman Maniac, a cheap slasher film “based” on a case Frank worked, you guessed it, thirteen years earlier. Frank is less concerned by the liberties the script takes than he is with the murders that start up on set. He and partner Emma Hollis (Klea Scott, the best part of an uneven final season) come to realize that the killer is reenacting horror films: Psycho (a shower murder), The Hitcher (a crew member’s finger in the set dinner), and more. Hollis reveals her love of the genre and she and Frank sit down to watch some tapes. Frank makes profiler style analyses of Michael Myers, Mrs. Voorhees, and Freddy Krueger, and while writer Michael R. Perry mixes up some of his references, there’s a priceless one-liner regarding the Friday the 13th franchise. “Where does it go from here?” Frank asks. “…a lot of people get killed?” Hollis offers.

“…Thirteen Years Later” is an attempt at a “comedy” episode, and often a clumsy and self-indulgent one. The KISS cameo feels fairly random, although they perform the banger “Psycho Circus” during the “concert” scene of the movie-within-the-show. (Their out-of-costume cameos are blessedly not distracting.) But the murder mystery plotline is fun, and the zany cast of characters provide a fair number of laughs. The actor playing Frank in Madman Maniac has fun riffing on Henriksen’s distinctive gravitas. While similar to Scream, the premise doesn’t feel like a rip-off. And what horror fan can resist an episode featuring clips from Halloween (1978) and references to offbeat titles like Motel Hell?

Millennium is sadly unavailable on streaming services, but well worth tracking down on DVD.