Readers, rejoice! All the elements Dan Brown used to such dramatic effect in Angels & Demons, The Da Vinci Code and The Lost Symbol are in full flower in his newest Robert Langdon thriller: impending global chaos and a frantic, day-long chase to avert it, a fanatically resourceful adversary, a beautiful and brainy companion and a pursuit route through some of the world’s most breathtaking architectural monuments. Hovering over the action is a menacing, ill-defined organization blandly called “the Consortium.” The enduring mystery here is why Langdon, who’s always on the run, hasn’t long since traded in his treasured Somerset loafers for a pair of Nikes.

Inferno begins with Langdon waking up in a hospital bed in Florence, Italy, and being told he’s just suffered a bullet wound to the head. Since his last memory is of walking across the campus at Harvard, where he’s a professor of symbology, this news comes as something of a shock. His attending physician introduces herself as Sienna Brooks. But before she can walk him through the events leading up to his present predicament, a spike-haired, black-clad woman assassin invades the hospital, apparently intent on finishing Langdon off. This launches Langdon and Brooks on a flight that will take them through the swankier museums and churches of Florence, Venice and Istanbul before the day is through. Early on, Langdon discovers he’s being chased because he may be able to discover the grand designs of renegade biochemist Bertrand Zobrist, who thinks the only way to save the world from overpopulation is by depopulating it with a plague.

The enduring mystery here is why Langdon, who’s always on the run, hasn’t long since traded in his treasured Somerset loafers for a pair of Nikes.

Even good-hearted Sienna seems swayed by Zobrist’s outlook. “Robert,” she tells him, “speaking from a purely scientific viewpoint—all logic, no heart—I can tell you without a doubt that without some kind of drastic change, the end of our species is coming. And it’s coming fast. It won’t be fire, brimstone, apocalypse, or nuclear war . . . it will be total collapse due to the number of people on the planet. The mathematics is indisputable.” So is Sienna really his friend or foe? Much of the appeal of Brown’s tale comes from never quite knowing where each character’s allegiance lies.

Zobrist, who is dead before Langdon enters the picture, leaves clues to his destructive intent by dropping references to Dante’s multilayered Hell, as described in the “Inferno” section of his Divine Comedy. Like Zobrist, Langdon is a Dante scholar and perhaps the one person who can decipher these clues before the plague is launched. Thus he is caught between the minions of the World Health Organization, which is determined to abort Zobrist’s plans, and those of the Consortium, which is just as resolute in ensuring those plans are carried out.

Although the general tone of the book is apocalyptic, Brown isn’t averse to having some fun at his own expense. At one point, Langdon phones his editor in New York at 4:28 in the morning to plea for the use of a corporate jet. “If you want to write Fifty Shades of Iconography,” his dyspeptic editor grumbles, “we can talk.” But Langdon pushes on, hoping to gain traction by citing his authorial integrity: “Have I ever broken a promise to you?” he persists. “Other than missing your last deadline by three years?” the editor muses peevishly before finally giving in.

Beyond providing readers the excitement of the chase and incidental lessons in art history, Brown also deserves credit for highlighting the very real problem of an increasing population vying for rapidly dwindling resources. Maybe it’s time for Langdon to turn activist.

Edward Morris writes from Nashville, and interviewed Dan Brown before he was famous.

Author Hallie Ephron’s third novel of suspense, There Was an Old Woman, hits all the right notes. As a respected mystery book reviewer for the Boston Globe and one of a talented literary foursome with sisters Amy, Delia and the late Nora Ephron, Hallie Ephron knows just how to tingle the spine or raise the hair on the back of your neck.

After Evie Ferrante’s alcoholic mother is hospitalized after yet another fall, Evie reluctantly travels from Manhattan to clean up her mother’s cottage at Higgs Point, where Evie and her sister grew up. It’s a spit of land at the southern tip of the Bronx between the East River and Long Island Sound, and Ephron atmospherically describes the marshy, semi-wild area in a gripping tale that skillfully connects past and present events.

Hallie Ephron knows just how to tingle the spine or raise the hair on the back of your neck.

Even as Evie notes the impoverished atmosphere and derelict condition of the house, she knows that something else is amiss. She finds an envelope with nearly $2,000 stashed among her mother’s possessions, and what’s with the case of expensive liquor—not the cheap kind her mother always buys? Looking beyond the front yard, she sees a growing number of empty lots where homes used to stand, and learns that some of the owners, though elderly, appear to have met a somewhat unexpected and premature death.

As Evie gets reacquainted with her mother’s elderly neighbor, Mina, the two form an unspoken alliance that will eventually uncover the lies and deception that have held the neighborhood hostage and led to its neglect. The beautifully drawn character of Mina portrays both the vulnerability and wisdom that comes with age, with many memorable portions written from her point of view. Mina’s long-held secrets provide a key to understanding the puzzle at Higgs Point, and she forges an important link with Evie’s life in the present.

Evie runs into Finn, an old childhood flame, and the attraction is rekindled. He adds another twist to the plot, as he is the leader of the Soundview Watershed Preservation neighborhood group that’s working to save the marsh and retain the area’s rural character. An aura of menace pervades, throwing into high relief the ongoing battle between the forces of preservation and those of unfettered development. There Was an Old Woman combines a unique storyline with characters that will stay in your mind long after you’ve put the book down.