Some of our kids make progress. They become the best person they can be, a triumph by anyone’s definition. Some of our children commit suicide. Others commit murder. They become that headline you’ve read in the paper: “Troubled Youth Opens Fire”; “Older Brother Slaughters Entire Family.” And people die, whether they had anything to do with it or not.

I know what you’re thinking. You’re thinking I took this job to save lost children like me. Or perhaps, even more heroically, I took this job to avert tragedies like the one that happened to my family.

I understand what you’re thinking.

But you don’t know me yet.

Thursday night, Sergeant Detective D.D. Warren was out on a date. It wasn’t the worst date she’d ever been on. It wasn’t the best date she’d ever been on. It was, however, the only date she’d been on in quite some time, so unless Chip the accountant turned out to be a total loser, she planned on taking him home for a rigorous session of balance-the-ledger.

So far, they’d made it through half a loaf of bread soaked in olive oil, and half a cow seared medium rare. Chip had managed not to talk about the prime rib bleeding all over her plate or her need to sop up juices with yet another slice of bread. Most men were taken aback by her appetite. They needed to joke uncomfortably about her ability to tuck away plate after plate of food. Then they felt the need to joke even more uncomfortably that, of course, none of it showed on her girlish figure.

Yeah, yeah, she had the appetite of a sumo wrestler but the build of a cover girl. She was nearly forty, for God’s sake, and well aware by now of her freakish metabolism. She certainly didn’t need any soft-middled desk jockey pointing it out. Food was her passion. Mostly because her job with Boston PD’s homicide unit didn’t leave much time for sex.

She polished off the prime rib, went to work on the twice-baked potato. Chip was a forensic accountant. They’d been set up by the wife of a friend of a guy in the unit. Yep, it made that much sense to D.D. as well. But here she was, sitting in a coveted booth at the Hilltop Steakhouse, and really, Chip was all right. Little doughy in the middle, little bald on top, but funny. D.D. liked funny. When he smiled, the corners of his deep brown eyes crinkled and that was good enough for her.

She was having meat and potatoes for dinner and, if all went as planned, Chip for dessert.

So, of course, her pager went off.

She scowled, shoved it to the back of her waistband, as if that would make a difference.

“What’s that?” Chip asked, catching the chime.

“Birth control,” she muttered.

Chip blushed to the roots of his receding brown hair, then in the next minute grinned with such self-deprecating power she nearly went weak in the knees.

Better be good, D.D. thought. Better be a fucking massacre, or I’ll be damned if I’m giving up my night.

But then she read the call and was sorry she’d ever thought such a thing.

Chip the funny accountant got a kiss on the cheek.

Then Sergeant Detective D.D. Warren hit the road.

D.D. had been a Boston PD detective for nearly twelve years now. She’d started out investigating traffic fatalities and drug-related homicides before graduating to such major media events as the discovery of six mummified corpses in an underground chamber; then, more recently, the disappearance of a beautiful young schoolteacher from South Boston. Her bosses liked to put her in front of the camera. Nothing like a pretty blonde detective to mix things up.

She didn’t mind. D.D. thrived on stress. Enjoyed a good pressure-cooker case even more than an all-you-can-eat buffet. Only drawback was the toll on her personal life. As a sergeant in the homicide unit, D.D. was the leader of a three-person squad. It wasn’t uncommon for them to spend all day tracking down leads, interviewing informants, or revisiting crime scenes. Then they spent most of the night writing up the resulting interviews, affidavits, and/or warrant requests. Each squad also had to take turns being “on deck,” meaning they caught the next case called in, keeping them stuck in a permanent vortex of top-priority active cases, still-unsolved old cases, and at least one or two fresh call-outs per week.

D.D. didn’t sleep much. Or date much. Or really do anything much. Which had been fine until last year, when she’d turned thirty-eight and watched her ex-lover get married and start a family. Suddenly, the tough, brash sergeant who considered herself wed to her job found herself studying Good Housekeeping magazine and, even worse, Modern Bride. One day, she picked up Parenting. There was nothing more depressing than a nearly forty-year-old single, childless homicide detective reading Parenting magazine alone in her North End condo.

Especially when she realized some of the articles on dealing with toddlers applied to managing her squad as well.

She recycled the magazines, then vowed to go on a date. Which had led to Chip-poor, almost-got-his-brains-screwed-out Chip-and now had her on her way to Dorchester. Wasn’t even her squad’s turn on deck, but the notification had been “red ball,” meaning something big and bad enough had happened to warrant all hands on deck.

D.D. turned off I-93, then made her way through the maze of streets to the largely working-class neighborhood. Among local officers, Dorchester was known for its drugs, shootings, and raucous neighborhood parties that led to more drugs and shootings. BPD’s local field district, C-11, had set up a noise reduction hotline as well as a designated “Party Car” to patrol on weekends. Five hundred phone tips and numerous preventive arrests later, Dorchester was finally seeing a decline in homicides, rapes, and aggravated assaults. On the other hand, burglaries were way up. Go figure.

Under the guidance of her vehicle’s navigational system, D.D. ended up on a fairly nice street, double lanes dotted with modest stamps of green lawn and flanked with a long row of tightly nestled three-story homes, many sporting large front porches and an occasional turret.

Most of these dwellings had been carved into multiple-living units over the years, with as many as six to eight in a single house. It was still a nice-looking area, the lawns neatly mowed, the front-porch banisters freshly painted. The softer side of Dorchester, she decided, more and more curious.

D.D. spotted a pileup of Crown Vics, and slowed to park. It was eight-thirty on a Thursday night, August sun just starting to fade on the horizon. She could make out the white ME’s vehicle straight ahead, as well as the traveling crime lab. The vans were bookended by the usual cluster of media trucks and neighborhood gawkers.

When D.D. had first read the location of the call, she’d assumed drugs. Probably a gangland shooting. A bad one, given that the deputy superintendent wanted all eighteen detectives in attendance, so most likely involving collateral damage. Maybe a grandmother caught sitting on her front porch, maybe kids playing on the sidewalk. These things happened, and no, they didn’t get any easier to take. But you handled it, because this was Boston, and that’s what a Boston detective did.

Now, however, as D.D. climbed out of her car, clipped her credentials to the waistband of her skinny black jeans, and retrieved a plain white shirt to button up over her date cleavage, she was thinking, Not drugs. She was thinking this was something worse. She slung a light jacket over her sidearm, and headed up the sidewalk toward the lion’s den.