Even in a sea of rotten serial-killer flicks, Joe Charbanic’s directorial debut sinks right to the bottom. Nasty, sadistic, ugly and pointless, it contains barely enough plot to fill a single episode of one of those terrible old cop series on NBC (“Hunter,” for instance), but it’s been padded mercilessly to feature length: it abounds with dreary flashbacks, lines of dialogue endlessly repeated in the apparent belief that all its viewers will be imbeciles incapable of catching their import the first time around,, shots of its FBI agent protagonist staring blankly into space to show his deep discontent, and scenes of his quarry strutting about cockily as he outwits his pursuers. Even with all this the dreary monstrosity times out at only 93 minutes, but it feels longer than “Lawrence of Arabia.”

The story can be dispensed with fairly quickly, since there’s so little of it. Ex-FBI man Jack Campbell (James Spader) is living the seedy life in Chicago, having moved there after failing to capture L.A.-based murderer David Griffin (Keanu Reeves) who, among many others, offed our hero’s married lover and thus sent him into a psychological tailspin. Griffin, feeling some sort of symbiotic relationship with his old nemesis, follows him to the Windy City and resumes his efforts there, taunting Campbell back into the field to duel with him once more. (One can presume some sort of homoeroticism at work here, but happily the script doesn’t follow up on the suggestion.) Campbell is also seeing pretty shrink Polly (Marisa Tomei), which should give you some idea as to who Griffin’s latest target will be.

The fundamental problem with “The Watcher” is that it generates absolutely no suspense apart from the grisly business of wondering precisely when Griffin will slaughter the victims he so assiduously stalks; and the cheap device of having the cops just miss locating the targeted women they’re searching for, or staging scenes in which hunter and hunted nearly bump into one another, merely accentuates the lack of storytelling substance. A few chases, on foot and by car, are tossed into the mix, but they come across as routine set-pieces, devoid of any imagination or excitement.

Under the circumstances the cast can hardly be faulted for phoning in their performances. Spader is his customary self–which means he’s intensely dour throughout; given the quality of the material, his perpetual look of pain is understandable. Presumably Reeves agreed to undertake the part of the hugely uninteresting killer (who, as is usual in such stories, seems inexplicably to have limitless resources to go about his bloody business without the need of a job) as a favor to Charbanic, who directed some of the videos made by his band; but his surfer-dude turn is reminiscent of his earlier roles than anything he’s done lately, and the shtick is pretty embarrassing. (It would probably be best for Reeves to avoid shooting any further projects in Chicago, too. It’s a lovely and photogenic locale, to be sure, but this fiasco and the 1996 clunker “Chain Reaction” suggest that the star and city do not mix.) Tomei has little to do but look either concerned or endangered; it’s another sad step down in the career decline of an Oscar-winner who might not have deserved her award, but surely doesn’t deserve tripe like this, either. Chris Ellis earns a few smiles as a tough-talking cop, even if his southern-sounding accent comes out of left field.

The denouement of “The Watcher” offers a final confrontation so extravagantly stupid as to set a new low for the genre; one can only be thankful at least that the killer’s M.O. of strangling his victims with piano wire isn’t portrayed as the result of trauma brought about by overly harsh music lessons in his youth (although such a silly diagnosis would have offered more of an explanation than any provided by the script). On a scale of “Se7en,” this soggy, unpleasant mess barely registers a 1.