It also had to be the priciest: $44.95. Flushed with annoyance, I forked over the money to the cable company with a click of the remote. The show was about to start, and David was texting me from inside the MGM Grand arena to ask if I was “in” yet. The price was almost a knockout blow. Like everyone else, I have come to presume that TV — like all information — wants to be free. Meaning, I want it to be free. $44.95 is as far from free as it gets when we’re talking media. It’s nearly the cost of a four-year subscription to Vogue, for heaven’s sake, or a month of cable or three James Bond movies on Blu-Ray!

Protest was pointless, and submission was inevitable. Once I paid my door fee, I was swept into a new world pulsing with color — a kind of red-light district with weird geniuses for tour guides who made the whole experience seem culturally crucial. The commentators for the U.F.C. have a style of truculent harangue all their own. Joe Rogan, in particular — the comedian, TV actor and host of “Fear Factor” — is so intense, relentless and silver-tongued that he made me feel as if I had wasted my life among slow-moving hayseeds and listless moralists until I lucked into the white-hot center of existence here with him.

As the preshow hype continued, I noticed an uncannily bright fighter named Frank Mir, who mixed analysis and bombast as if they were the only true martial arts. In documentary-style interviews, he kept praising his opponent. I couldn’t believe, when I saw Mir handily win his fight, how brazen had been his pysch-out. I was also struck by the worldliness of the fighters. An early fight pitted Cheick Kongo (“fighting out of Paris, France”) against Mostapha Al Turk (“fighting out of London, England”).

The Octagon is the ring for the U.F.C. It has eight sides and is enclosed by a chain-link fence. The name “Octagon” really seems like a way to keep you from calling it what it is: a cage. In spite of this and other efforts to make Ultimate Fighting seem less thuggish — the immaculate pay-per-view display, the visibility of women in the audience and the intelligence of the spitfire commentary — you can’t miss the raw, back-alley character of the fights. Veins bulge and faces go blue as fighters seem intent on choking their opponents. Blood is shed; bones break; contusions develop before your eyes. Men are felled by “accidental” strikes to the groin (along with eye-gouging and biting, such strikes are prohibited, but I saw several). The commentators insist that everyone’s obeying regulations, but the fighters seem murderous nonetheless. Until, that is, each fight is over, and the fighters are typically praised for showing “class” in making sure an opponent is still breathing.

One way the violence of the fights is muted is quite literal: the sound feels dialed down. If “Braveheart” and other war movies have shown that the audio mix is what allows an audience to experience violence viscerally, then these U.F.C. telecasts, which don’t amplify the sounds in the Octogon, suggest that a quiet fight comes across as a cleaner fight. No crunch of bones, no crack of noses, no squish of damaged soft tissue. From David’s texts, I could tell he was “feeling” the fights much more than I was.

Too much has been made of John McCain’s campaign to ban Ultimate Fighting as “human cockfighting,” but some of the illicit adventure of a cockfight did attend the U.F.C. telecast I saw. I felt myself transported and included among people of high spirits, strong nerves and a clear-eyed sense of man’s depravity. (Joe Rogan called our violent urges “weird, chimpanzee D.N.A. stuff.”) I’m not in this company often, and it was heady. We were seeing it all at once, all together. David’s texts grew more rapid. “I just saw Rampage!” he said, referring to his favorite fighter, Quinton (Rampage) Jackson.