The colorful, swirling shapes that open The Night Listener almost beg to be considered more than just pretty pictures. Opening credits appear over a succession of fractured images not unlike the kind you see through a kaleidoscope, where certain sections of reality are distorted and multiplied while other bits of information get left out entirely. The effect is intriguing at first but gets old quickly, a one-trick pony prompting our brains to discern patterns where they might not actually exist.

That's how the rest of The Night Listener operates as well, with snips and snaps of story adding up to little more than a big tease. What we have here is yet another one of those films that gets off so thoroughly (and assumes that we do, too) on scaling the slippery slope between truth and illusion that it neglects to supply us with something to sink our teeth into.

The primary navigator of that slippery slope is Gabriel Noone (Robin Williams), a late-night talk-radio personality who specializes in spinning tales that may or may not be true. The movie's first half-hour dutifully dangles various tidbits concerning Noone's personal life (he's gay, we learn, and in a bit of funk after splitting with his longtime companion), but the story kicks in only when Williams' character is sent an unpublished autobiographical manuscript by one his fans, a terminally ill 14-year-old named Pete (Rory Culkin).

The San Francisco DJ becomes obsessed with the Wisconsin teen's rough but brilliant account of horrific childhood abuse, and the two soon enter into a long-distance relationship, chatting regularly on the phone but never actually meeting. Gabriel also occasionally speaks with Pete's guardian, Jess (Toni Collette), but when he finds himself nagged by a curious similarity between the voices of the adult guardian and her young charge, Noone begins wondering if the two might actually be the same person. From there it's a short step to doubting every word in Pete's manuscript, and even wondering if the boy actually exists at all.

The irony here, of course, is that No one is himself someone who has generated a successful career from embellishing the truth for popular consumption, creating more interesting realities by playing fast and loose with the facts of life. The movie is not particularly subtle in setting up parallels between its fabricating characters. Noone, who also serves as the movie's narrator, makes a nuisance of himself by repeatedly harping on how one person's reality is another person's illusion. It's bad enough when a movie inadvertently becomes little more than maddening enigma, but The Night Listener adds a voice-over hell-bent on drawing our attention to just how maddeningly enigmatic it all is.

Riddled with questions and suspicions, Gabriel finally hops a flight to Wisconsin in search of answers but finds things even murkier once there. Toni Collette turns in a solid performance as the vaguely ominous Jess, but The Night Listener takes a turn for the worse once the action shifts to Pete's home turf, with Noone racing up and down various blind alleys in search of a truth that's always just out of reach. The movie is a puzzle with a few of the pieces deliberately removed — almost all red herrings with a handful of suspenseful moments leading nowhere and a few gratuitous scares. At one point, for no particular reason, we even get a bald-headed boy leaping up at us from his hospital bed, shrieking and hissing like a pod person from Invasion of the Body Snatchers.

The brief moments of incongruous excitement only make us more aware of how listless the rest of the film is. Some viewers may actually be intrigued by The Night Listener's failure to supply answers to its various conundrums, but what's not so easily rationalized is the solemn and static manner in which the film goes about its business. The lack of dramatic punch almost seems by design, as if The Night Listener were being guided by the proposition that a film has to be a bit dull in order to prove how smart it is.

Fortunately, we still have movies like The Descent to show us just how wrong that line of thinking is.

An expertly crafted and wildly scary bit of business, The Descent is the summer's best thinking-man's horror flick. Maybe we should make that thinking woman's horror flick, since The Descent, which is basically an infinitely better version of the recent The Cave, features a smart, able and exclusively female crew plunging into terra incognita and facing down their most unmanageable fears.

After a brief prologue in which the movie's only bona fide male is tragically dispatched (an event that becomes crucial to the film's later sections), The Descent introduces us to six young women gathered together in the mountains of Appalachia for an annual bonding/braving-disaster experience. Nothing much happens for the first 20 minutes or so, giving the film ample opportunity to define its characters and their relationships, but you can feel the tension simmering even from the outset. By the time the women begin lowering themselves into that ominous cave where we know they shouldn't be going, the creepiness is palpable in every frame. And when the truly bad stuff begins happening, about midway through The Descent, the fear factor is practically off the charts.

Director Neil Marshall, who previously gave us the cult gem Dog Soldiers, masterfully blends psychological horror and scares of the more visceral, blood-soaked variety, evoking Deliverance and The Blair Witch Project with equal confidence, with a touch of The Hills Have Eyes for good measure. Marshall lays on the dread methodically, relentlessly, segueing from fly-on-the-wall mock-doc footage to more slickly cinematic moves, putting us right in that claustrophobic universe with the beleaguered characters.

The dialogue, when it comes, is crisply naturalistic, and, without putting too fine a point on it, there's subtext aplenty to mull over for those disposed toward mulling (strong, man-less women fighting panic in a deep, dark cave — what's not to mull over?). Be warned that The Descent is also extremely tough stuff, especially in its later sections — intense, unapologetically gory, occasionally even disgusting (and yes, there are monsters) — although it's worth noting that the film's distributor, Lionsgate, has softened things up a touch by revising the original take-no-prisoners ending. The original, infinitely more challenging ending is still out there in the world, however (available on DVD in the UK, where the film was released last year), so I suppose we should all just shut up and be grateful that someone's still looking out for the tender sensibilities of American viewers.