Pearl was wearing a green nylon collar with a paper tag that read, in pencil, F-417. The tag came off in the car on the drive south from Indianapolis. Her new collar, a soft pink one, was waiting for her at the house outside Bloomington.

She is five years old. She is a tricolor beagle, fifteen inches at the shoulder, twenty-two pounds. She has never been outside.

Pearl is one of thirty-seven beagles released this month by a research facility in central Indiana to the Beagle Freedom Project, a nonprofit that has, since 2010, rehomed roughly four thousand dogs retired from laboratory testing. The facility, which has asked not to be named under the terms of the transfer agreement, breeds and houses beagles for non-terminal pharmaceutical safety studies.

The Beagle Freedom Project does not contest the legality of such facilities. It exists to take the dogs when the studies are over.

Pearl arrived at her foster home, the second-floor apartment of a graduate student named Wesley Imani, at four o'clock on the afternoon of May 12. Imani has fostered three previous laboratory beagles and knows the routine.

The first hour, he said, is always the same. The dog does not move. She stands in the middle of the living room floor with her tail down and her ears low. She does not eat. She does not drink. She watches everything.

Pearl watched for ninety minutes. Then she lay down on a folded blanket Imani had placed by the couch and slept for four hours.

Pearl approached the threshold three times and turned back twice. The third time, she stepped over it.

The next morning, Imani opened the back door, which leads to a small fenced yard shared with the downstairs apartment. He stood by the door. He did not coax her. He had been told, by the Beagle Freedom Project's intake coordinator, that coaxing rarely works the first time.

Pearl approached the threshold three times and turned back twice. The third time, she stepped over it.

The grass, Imani said, stopped her. She lifted one paw and held it up. She lowered it. She lifted the other. For perhaps a minute she stood in the doorway with both front paws on the concrete step and both back paws on the grass, looking down.

Then she walked forward six steps and put her nose in a patch of clover.

Imani has video of this. He took the video, he said, because the intake coordinator had asked him to, for the organization's records. The video is forty-three seconds long. The dog does not run. The dog does not bark. The dog walks slowly across the yard, smelling things.

Beagles, the breed, are famously nose-driven. They were developed in England in the seventeenth century to track hare by scent. The olfactory bulb of a beagle contains roughly two hundred and twenty-five million scent receptors, compared to roughly five million in a human. What a beagle smells when she puts her nose to clover is not, in any meaningful sense, what a person smells.

For Pearl, who had spent her life smelling stainless steel, kibble, disinfectant, and the other dogs in her cohort, the back yard in Bloomington was, by Imani's description, an overwhelming experience.

She stayed out for forty minutes. She came back in, drank a full bowl of water, and slept again.

The Beagle Freedom Project's medical coordinator, Dr. Lauren Pohl, who reviews intake records for all incoming dogs, said Pearl arrived in better physical health than many. She has all her teeth. Her coat is reasonably good. She has had her ears tattooed with an identification number, which will fade over time but will not entirely disappear.

What Pearl does not know, Pohl said, is how to be a dog.

"She has never climbed stairs," Pohl said. "She has never met a cat. She has never heard a doorbell. She does not know what her name is, because she has never had one. All of that comes with time. The first week is grass and quiet and food on a schedule."

Pearl will stay with Imani for approximately three months. After that, she will be placed with an adoptive family that has already been screened. The family lives in Indianapolis. They have a yard with clover in it.

On the morning of her fifth day in the apartment, Pearl walked to the back door on her own and looked at Imani.

He opened the door. She went out.