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.