"Keeping Safe the Stars," by Sheila O'Connor Harry Potter, Oliver Twist, Dorothy Gale, Huck Finn, Pippi Longstocking, Anne Shirley: ­orphaned protagonists in children's books are legion. They're also the stuff undergraduate English lit classes are made of. Whatever our age, parental death, abandonment and neglect immediately tug at our sympathies, showing us the fearsome realities of the adult world, rendered starker when seen through a child's eyes. There is even greater satisfaction when the young protagonists find the strength and resilience to persevere on their own. The predicaments of the parentless or the barely parented have historically preoccupied the novelist Sheila O'Connor. In her 2003 adult book "Where No Gods Came," 12-year-old Faina is sent to live with the alcoholic and housebound mother she's never met. In her 2011 middle-grade book, the magical "Sparrow Road," 12-year-old Raine is finally reunited with her long-lost father, a man she didn't know was alive. In her touching new middle-grade novel, "Keeping Safe the Stars," the three Star children are orphans: the 13-year-old narrator, Pride; her 11-year-old sister, Nightingale; and their 6-year-old brother, Baby. Those aren't their real names, but the nicknames their mother gave them at the New Mexico commune where they were born and raised until both parents died and their grandfather, Old Finn, took them in at Eden, his rural Minnesota homestead. When Old Finn leaves Eden for a visit to the doctor and doesn't return, taking care of the Stars falls to Pride. A crotchety, intellectual former radical who home-schools his grandchildren, Old Finn doesn't trust outsiders and never asked his few local friends for help. The Star kids share his fierce insularity and independence, so when they realize they'll need to find a way to get to the regional hospital in Duluth to inquire about his condition, and to find the money to do so - they've already spent his last $10 bill in the grocery stash on staples - they're not sure how to proceed without alerting others to their situation. Some busybody could call Child Protective Services and split up the siblings. It's 1974, so without the Internet, where the Star kids might be able to Google "encephalitis," look up the phone number of the Duluth hospital and search for the mysterious author of the love letters they've found in Old Finn's drawer (a painter named Justine who could prove their savior), they have to do things the old-fashioned way: through hard work, and orphan ingenuity and self-reliance at its best. This means riding their horses into town for groceries; starting up a makeshift tourism business and using their ponies and some popcorn to collect enough change for the bus to Duluth. There's also Pride's ill-fated experiment with costuming and makeup in the hopes of looking grown-up enough to get Old Finn's prognosis out of the doctors. Old Finn taught them that any outsider interest in Eden would lead to trouble; the challenge is for them to slip away without someone asking why there's no adult around. The Stars" dedication to one another, intensified by their shared parental loss, provides the novel's emotional backbone. "However long Old Finn's fever lasts," Pride tells her siblings, "we're going to have to stay on the same side. Stick together as the Stars. The way Mama always said. Instead of breaking them apart, their troubles lead them to fight even harder to keep the family intact. Old Finn has taught them well, and it is against the odds that they're able to survive on their own and find their way to Duluth. While "Keeping Safe the Stars," at a slow-paced 297 pages, is long for a ­middle-grade novel without a complex narrative, and O'Connor's otherwise graceful prose falls victim to a literary tic of writing in abrupt fragments ("She'd already divided her last can of mushroom soup for supper. Filled us up on stale saltines"), it's still a marvel to watch these three children band together - and to be there when they, and Old Finn, realize that even the most fiercely independent of us will eventually have to rely on other people to make it through. Whitney Joiner is a co-author of "The Drama Years," a book for parents of middle-school children.