Gentle readers who want to be surprised as they watch Hit & Miss should consider this the mother of all spoiler alerts. Just stop reading now and go look at the comics. I bet Calvin & Hobbes is pretty funny. (What? We don’t?) And any truly gentle readers should probably avoid this show. Seriously. Unplug your set while it’s on. Don’t take any chances.

OK, anybody who’s still reading, here’s what happens in the first three minutes of Hit & Miss. A stark, hooded figure stalks a man through a parking lot before drawing a silenced pistol and shooting him several times, obviously a professional hit. Moments later, the killer pulls off the hood to apply her lipstick: surprise, not a hit man, but a hit woman. And moments after that, as she strips to shower, an even bigger surprise: a bulge amid the curves. Our hit woman is transgendered.

And there’s one more surprise, for her as well as us, in a letter she reads shortly afterward — she’s now a single mother. Unbeknownst to her, she fathered a child back in her XY chromosome days, and the little boy’s mother has died of cancer.

I can hardly blame you if this sounds like the all-time stupidest collection of television gimmickry in a single show. Yet it’s not. Hit & Miss, once you get past the successive bombshells of its opening minutes, is a painful yet endearing drama about trying to build a family in a landscape blighted by loneliness and rejection. (Speaking of which, if you don’t have a DirecTV satellite dish, better cultivate a friend who does; that’s the only way to see Hit & Miss.)

Chloe Sevigny, in her second brush with transgenderism (she played the girlfriend of Hilary Swank’s doomed transgendered teenager in Boys Don’t Cry), stars as Mia, the chilly contract killer who’s saving up her murder money for the surgery that will complete her conversion to female.

Parenting is an uncertain business at the best of times, children coming as they do without instruction booklets, but Mia’s precarious approach to Ryan, the 11-year-old son she didn’t know she had, necessarily takes place in almost entirely uncharted areas. Her erratic maternal skills — even in a feminist millennium, mothers who teach their sons to box or shoot foxes off the back porch with night-vision sniper scopes are relatively rare — threaten to dissolve entirely at questions that awaken her own ancient gender anxieties, like, “When did you realize you were a girl?”

Their relationship is further complicated by the grief and alienation of the other three children left behind by the death of Mia’s former girlfriend. Sixteen-year-old daughter Riley resents the intrusion of a stranger into the modern-day nightmare of a Brady Bunch she’s trying to hold together. “We don’t need you here and we don’t want you here,” she bitterly declares. Her younger brother Levi goes right for the jugular, calling Mia “freak.”

And though family baby Leonie, just 5, is too young to be bothered by gender preconceptions, her desolation over the death of her mother often surfaces in ways that are as surprising as they are devastating, as when she asks out of her ballet class: “I can’t dance today, Miss. I’ve got breast cancer.”