As we prepared to look closely at the rats, Markowski cautioned me not to make too much of them; he seemed to be saying that I shouldn't get caught up in rat lore and rat mystique ? the images of rats as big as cats, rats that control the city's underworld. They were only rats, he explained to me, easily sedated, easily controlled, good scientific subjects, even in the wild. As he spoke, he opened the garbage bag covering one of the cages. Li treated two cotton balls with halothane. She dropped the cotton balls into the garbage bag and twisted it shut tight. This was an attempt to put the rat to sleep.

In a few minutes Markowski looked into the garbage bag at the rat. He shook his head as he closed the bag. Markowski looked a little incredulous. "He's livelier than he was before," Markowski said.

They increased the dosage of tranquilizer, putting in three treated cotton swabs this time. The wind was picking up. They waited and looked in the bag again. The rat was still alert. "That rat's one tough bastard," Markowski said.

Markowski increased the dosage again.

Finally, the rat looked unconscious, its tail limp, though when Markowski took it out of the cage he quickly discovered that it was still awake. He held the rat down on the ground with his hands and placed a halothane-treated swab directly over the rat's nose, holding the cotton with tweezers. The rat was going from groggy to woozy to sleepy to asleep, and as this happened, I was able to see that the rat was a large female, measuring, as we later determined, about 11 inches long, not including the tail, which was close to another 10 inches and looked to me like something belonging to an armadillo. At last the rat seemed at peace. Markowski held the rat down on the ground and plunged the needle into its chest, aiming for the rat's heart. He drew out the rat blood and bottled it; the blood was a deep, rich mammalian red. I looked away, over at Ruiz, who was still standing next to the van. Markowski put the rat in a freezer bag, with another dose of halothane. The halothane would kill the rat: it slipped from rat sleep to rat death.

Denby, like the rest of us, made a choice in life - or choices, really. He decided that he was going to be a Writer, and that generally means - leaving aside the Susan Collinses of the world - that you aren't going to get rich. But if you work hard and keep a steady moral compass, you may be able to live a very fulfilling, never mind cool, life. It's kind of vicariously cool, but it ain't bad.

Denby did not decide to go work on Wall Street, which he could have done. Obviously he has the requisite brain cell capacity, etc. Wall Street is a funny place. It is the only business, or occupation, where the line function (sorry for the Harvard Business School lingo) is to make money. In other words, at Monsanto you make chemicals, and by the way you get paid. At Ball State, you teach and by the way you get paid. At The New Yorker, you write, and well, you get the point. ... But on Wall Street, you take money and use it to get more. The whole point is to make a lot of money. (There is nothing more sickening that someone from Goldman Sachs saying [and they do this more than anyone] that what they are really doing is creating value for their customers. Twaddle!)

But let me dribble out some credit here. Working on Wall Street is tough. Very tough. Yes, there are a few Ringo Starrs out there, who just happen to be at the right place at the right time, but mostly it is grueling. Long hours. Boring like you would not believe. Lots of assholes. Constant temptation to cross the line. And if you navigate through this and you have a brain, yes, you too could make, let's say, $750,000 a year. Denby could have chosen this life.