Sunlight pushes through a glass roof smeared with bird droppings, wringing summer's heat upon those massed in the visitors' lobby of the Dallas County Jail.
The jail houses thousands, accused of petty larcenies and vicious murders and all crimes between. Accused of the worst is 22-year-old Thomas Johnson. Last fall, he was charged with taking a machete to a jogger's neck for reasons unknown perhaps even to himself.
Johnson has sat in jail ever since. Ruled unfit for trial, awaiting a bed at a mental hospital, he rarely leaves his cell and takes no visitors — not his lawyer, not his father.
And yet, all summer, through the jail lobby came Dave and Lisa Stephenson — they of suburban comforts and an undying faith in redemption.
Weekend after weekend, they follow the scuff of tiny sneakers through a hall of endless turns, into a guarded freight elevator that drags them up the jail tower's throat. They step out into a row of cramped booths where men in gray stripes coo through glass at children. And they wait for Johnson, and he never comes.
Then they walk back the other way, sometimes silent, sometimes one in tears.
If any man resists salvation, it is Thomas Johnson. Before the killing, he abandoned college football stardom and the Stephensons' home when they tried to help him.
But Dave and Lisa are missionaries, pushing ever deeper into a broken world in search of those who need their help — be it change for a bus ride, kind words for a stranger or loyalty to a mentally disturbed killer.
Dave calls it "scattering seeds of encouragement." Lisa calls it "trying to be a light in a really dark place."
This jail, and the mind of the young man locked in it, are the darkest places they've yet found.
*
Dave and Lisa live by a code. They learned it from the Bible, and it's simple on its face: Treat people well. Encourage them and help them.
"You just try to dignify everybody without being mean and angry," Dave says.
Twenty years ago, the code saved their young marriage from petty squabbles. It taught them to think of others — first each other, then friends, then total strangers.
Their foyer is plastered with pictures of church trips to desperate countries, where Lisa uses Bible pictures to explain salvation and sin.
Their hall is lined with photos of young men from broken neighborhoods in Dallas who have stayed with them. One had been given away by his parents at a gas station to be raised by an uncle. Another's father had killed his mother, then himself.
The Stephensons give these young men shelter. They help them find jobs and colleges.
In the spring of 2014, they were volunteering at a football game at a run-down South Dallas high school when the coach pulled them aside and told them of Thomas Johnson.
A star receiver from Skyline High with a scholarship to Texas A&M University, Johnson disappeared from the A&M campus after just 10 games, prompting a police search and reports that he walked part of the 200 miles from College Station back to Dallas.
Read our story on the search for Thomas Johnson in 2012
At the time, Johnson was charged with stealing his aunt's van and trying to drive it back to college. Dave and Lisa heard all this and knew he needed help. That's when they first ascended the jail tower and squeezed into a grimy booth to see him.
Barely out of his teens then, he spoke of his regret and asked for help through the security glass.
The Stephensons convinced a judge they could rehabilitate Johnson. They picked him up at the foot of the tower and drove him back to their creek-threaded property in Farmersville — a young, ruined athlete who brought nothing but the clothes on his back and a secret sickness in his brain.
*
Johnson's brief stay tested the Stephensons' code. Their guest was alternately effusive and moody, silent then laughing inexplicably. He slept through appointments, called no one, piled old food and dirty clothes about his room. The Stephensons, who have no children of their own, argued over what to do, with Lisa taking on the role of disciplinarian and Dave the happy-go-lucky dad.
After several weeks, Lisa was preparing to escape for an evening with some friends and a bottle of wine when Thomas got a call from his mother in South Dallas. When he hung up, he insisted on going home to her.
Dave and Lisa told him that doing so would break the terms of his release. They say he told them he'd rather go back to jail than stay with them.
They let him go. He never returned.
"My biggest regret in life at this moment is that we did that," Lisa says.
A year later, on the first chill day of 2015, they were sitting in the living room when Lisa heard Dave gasp from the other couch.
He looked up from his phone and said, "Thomas just killed somebody today."
Beneath a bridge, police say, Johnson had murdered a runner named David Stevens with a machete along the White Rock Creek trail — a killing so horrific that more death spun out of it. Stevens' wife, Patti, later wrote a goodbye note and sealed herself inside her garage with the car engine running.
Related: Read about the jogger's killing and his wife's suicide
Dave remembers tears and prayers and frantic phone calls in the aftermath. Lisa does not. Her first memory after the killing, three days later, is being back in the jail tower with Thomas' beaming face behind the glass.
"You look so handsome," Lisa told him. "Do you remember me?"
"Of course I remember you, Ms. Lisa."
"I just wanted you to know how much God loves you. Do you believe that?"
"Yes, ma'am. I do."
He looked as peaceful as they'd ever seen him. The Stephensons walked out sure that Thomas was insane.
So they kept coming back: the twisting hall, the growling guards, joining the weekly parade of children and parents, husbands and wives.
They never spoke to him of the crime. They talked of old girlfriends and rescued dogs, sent him letters between visits, encouraging him to be kind to other prisoners.
"We pass God's love on to others," Dave once wrote. "Whether it's the mailman for me or someone in jail for you."
They say they grew closer to Johnson in those weeks than they ever had while he lived with them. Once, they talked so long the guard came to fetch him before they were done.
"When he saw that I was going to care about him even though he was bad, maybe that opened something up in his heart and mind," Lisa says.
And then, something closed.
In April, a judge ruled — and even prosecutors agreed — that Johnson was unfit for trial, ordering him to be transferred to a state mental health hospital in the countryside. The Stephensons were relieved. They thought he would start getting real help.
But they didn't know that Dallas County prisoners often wait months for a psych bed. Johnson was still in the jail the next time the Stephensons came to visit.
He didn't come out of his cell.
Nor did he see Dave and Lisa the next weekend, or the next. Still, they would drive nearly an hour and sit in the visiting booth, thinking Thomas might be finishing lunch, worrying he might be losing his mind in isolation.
"They tell you he won't come, and you've got to walk that whole long way," Lisa says. "You've gotta go all the way back down, get in the elevator, wind that whole hallway down." To take their minds off rejection, they'd often say a kind word to a child passing the other way.
After the third refusal, Dave and Lisa held hands in the hall, silent. Lisa held her tears until she reached the car.
"I can't do this anymore," she said.
On the drive home, Dave compares himself to a perennial flower, and Lisa to a giant sequoia.
"She's got to dig 20 yards deep to put in a tree," he says. "Those are deep roots. I can go down and see Thomas and if he doesn't show it hurts. But there's a scar with Lisa."
Dave kept going to jail, every other weekend or so. Lisa's guilt grew each time she stayed home. In all the horror stories they've heard from deep inside the city, someone gives up on someone at the beginning.
"There's the part of me that feels if something happens to him, I can at least say, 'Hey, we at least did everything we could to try to encourage him,' " Dave tells Lisa one day.
Lisa wipes her eyes and resolves to go back.
*
They pray before driving down together. They say a kind word to the guard at the metal detector, and get a smile in return.
Up in the tower, Lisa puts her hands behind her back and speaks up into the control room's dark window with a breath of hope.
"Thomas has refused all visitors the last six times we've come here," she tells the glass. "Is there any way a guard could tell him our names?"
She steps back and waits, wringing her fingers. She smiles at a little girl in line. The girl hides her face in her mother's shirt.
After five minutes, a voice calls Lisa back to the window: "He don't want visitors. It's not just y'all. He don't come out for no one."
"Bye, sweet pea," Lisa tells the girl, eyes boiling. Dave calls the elevator, and they sink back to the foot of the tower.
When the doors open, she sees the same guard at the metal detector and wants to walk past him — to escape the jail as fast as she can.
But she's Lisa Stephenson, and she has a code. So she gives the guard a high five and stops to talk a while.
They tell him of the prisoner upstairs who won't leave his cell. They ask for ways to help him, when all hope seems lost.
As the Stephensons head for the door, the hall seems not so twisted after all.