What do the books in this latest crop of middle-school fiction have in common? Plucky, sometimes lonely, heroes; a little magic; a lot of humor, and no vampires. Oh, and Minnesota authors all. "Mamba Point," by Kurtis Scaletta. (Alfred A. Knopf, 288 pages, $16.99)

Sweet, nervous Linus from Dayton, Ohio, moves to Liberia when his father gets a job in the Embassy. A new beginning gives Linus the perfect opportunity to try on a new, brave persona, but it is his unique relationship with a deadly black mamba snake that brings about real change. Linus doesn't like snakes, but this terrifying serpent keeps showing up wherever he goes, and eventually the lonely boy comes to accept it as his kaseng -- a sort of Liberian familiar. The story's tension builds whenever the black mamba appears; the snake rubs against Linus and entwines his legs and behaves sort of like a pet dog, but the reader can never relax, sensing the danger that Linus chooses not to see.

Linus, who narrates the book, is utterly believable, innocent and worried and easily distracted, like any 12-year-old. "It was a big deal to have a servant. ... If I wanted a bologna sandwich, would I just ask the servant guy to make me one? If I did, would he know how to do it, with a little mustard between two slices of bologna and mayonnaise but not mustard on the bread and one leaf of lettuce and a slice of tomato but never the end of the tomato? Would he take the red ribbon off the edges of the bologna? Did they even have bologna in Liberia? There was a lot to think about." There sure was. Where were we again? Oh, yeah. "Mamba Point." Fun book.

"Elvis & Olive: Super Detectives," by Stephanie Watson. (Scholastic Press, 240 pages, $15.99)

The second volume in the Elvis & Olive series has our heroes scouring their neighborhood for mysteries to solve. Annie, aka Elvis, and Natalie, aka Olive, take on problems both small (neighbor Harold's missing library books) and large (Annie's missing mother).

In between, Natalie wrestles with her feelings for a cute boy named Steven, Annie wrestles with her feelings of rejection and both girls put their hearts into trying to help an elderly neighbor stay in her house. All in a day's work for the E&O Detective Agency.

"The Shadows: Volume One of the Books of Elsewhere," by Jacqueline West. (Dial Press, 256 pages, $16.99)

Another Olive! This one is unflappable and smart, a bit of a loner, adventurous and bespectacled -- just the kind of heroine I would have admired back when I was in fifth grade. Olive is the only child of a couple of rather obtuse mathematicians, who move into a creepy old mansion in a small town. While exploring the house on her own, Olive discovers that she can slip into the paintings that hang on the walls. But once inside, can she get back out again? And can the images in the paintings get out, too? Red Wing author Jacqueline West is first a poet, and you can tell; her writing is lyrical and lovely, laced with wry humor. She never writes down to her audience, but sprinkles in allusions and jokes that some readers will get and other readers will just happily skip over to get to the next adventure. Middle-grade writing as it should be.

"Magic Below Stairs," by Caroline Stevermer. (Dial Press, 199 pages, $16.99)

Magic, wizards and a brownie -- the talking, inedible kind, dressed in a little green suit. Young Frederick Lincoln gets plucked from the orphanage simply because he happens to fit into the uniform of a servant boy, and off he goes to a new life with Lord Schofield, the famous wizard. It might have been chance that got him the position (chance, or the help of his brownie friend, Billy Bly), but it's his wits and skill that keep him there. Frederick is a clever, observant kid who can tie a complicated cravat like nobody's business and knows how to sharpen knives (and razors). And when an evil spirit that once was vanquished returns to the castle, Frederick takes it upon himself to do something about it. Stevermer's writing is easy and fluid; this book is a charming, pleasant read.

"Emmy and the Home for Troubled Girls," by Lynne Jonell. (Square Fish, 358 pages, $6.99, new in paperback)

The sequel to "Emmy and the Incredible Shrinking Rat" finds Emmy Addison still lonely, still embarrassed to be hanging out with the rats, mice and chipmunks that she can communicate with (thanks to the magical powers of a rat bite). All she wants is to fit in with her human friends, but when she tries to cozy up to a group of girls her own age, she inadvertently ends up putting Sissy, one of the sweeter, more clueless rats, in danger. And then there's nothing to be done but shrink down to rat size (achieved by a second rat bite) and try to make amends. There's also an evil rat to be contended with, and four missing girls to be rescued. Jonell's book is deeply absorbing, just complicated enough to keep you guessing, and lovely in the light way she handles the moral -- you get it, but you never feel preached to.

"Billy Bones: Tales From the Secrets Closet," by Christopher Lincoln. (Little, Brown, 287 pages, $6.99, new in paperback)

Who knew that the Afterlife was such a complex place, run by pompous midlevel bureaucrats and stiff with regulations and rules? Endearing skeleton boy Billy Bones and his parents live in the secrets closet in a wonderful old house that is home to a truly evil master and laced with secret passageways and hidden rooms. Inside their closet, the Bones family categorizes, documents and files the secrets and lies that come from the household -- and they are legion. Every now and then one is exposed to the light of truth, and there's the most spectacular explosion as the secret disintegrates. When Billy is discovered by a lonely flesh-and-blood girl, Millicent, they become best friends and quickly discover enormous secrets about Billy himself. Christopher Lincoln's book is new in paperback, and its sequel, "Billy Bones: The Road to Nevermore," was published last fall.

Laurie Hertzel is the Star Tribune Senior Editor for Books.