In a dead-end American town, a young woman named Flynne fills in for her brother, beta-testing an online game that seems to involve fending off paparazzi in some futuristic London skyscraper.

When she witnesses a murder, she decides maybe it’s not a game after all – a fact confirmed when gunmen hired by forces from the 22nd century show up to kill her and her family, leaving her caught between two super-powerful organizations in a swiftly escalating conflict that could reshape their present, and alter her future.

Although it veers back and forth between near-future and further on, “The Peripheral,” science-fiction master William Gibson’s first novel in four years, is not really a time-travel story. It’s a story of people making choices – sometimes by habit, sometimes forced by circumstance, sometimes guided by the better angels of their nature – and how those choices can ripple through time, or spiral out of control.

And as in the best of Gibson’s novels, it’s a story of people taking a stand, often despite themselves.

In Flynne’s world, dominated by giant corporations, soaring health care costs and soldiers from unnamed wars putting their lives back together, most folks are just hanging on. Drones are commonplace – for delivery and defense – and so are corruption, 3-D-printed weaponry, illegal pharmaceuticals and the cynical use of power. Flynne and other decent people survive by keeping their heads down and consciences clear.

The future-world that Flynne gets a glimpse of is dominated by kleptocracy, Machiavellian plotting, frantic innovation and an alarming disregard for consequence. When the murder she witnesses brings the killers into her timeline, a rival faction from the future steps in to protect her – and, in the process, changes the present in a way that severs its relationship to the future.

Flynne’s principal connection to that future is Wilf Netherton, a publicist whose brief affair with a client – a performance artist whose self-celebrity-styling makes the Kardashians look naive – is tangled up in what Flynne witnessed. They connect not by physically traveling through time, but through “peripherals”: drones inhabited virtual-reality-style that allow them to experience and communicate in the other reality without leaving their own.

To bring matters to a head, Flynne must “travel” to Wilf’s world and identify the murderer. But getting her there alive – amid a dizzying military and capitalistic buildup in her world and devious high-tech dealings in his – will require more than technical cunning on both sides of the looking glass.

It’s been awhile since Gibson – the guy who coined the term cyberspace in his landmark 1984 novel “Neuromancer” – has been this science-fiction-y. His last three novels, capped off by 2010s “Zero History,” were set in a very-near-future at once familiar and alternate-universe. (Gibson’s other often-quoted statement, “The future is already here – it’s just not very evenly distributed,” echoes through all of his writing.)

But even when “The Peripheral” is dealing in futurescapes – as in a tour of London post-“jackpot,” a tumultuous time between both realities when, basically, everything went to hell – Gibson doesn’t obsess with explanations of how the tech works, or how the universe operates.

Instead, he focuses on his characters’ interactions with the worlds around them, teasing out answers in real narrative time and allowing the characters, and readers, to make their own adjustments as needed in realities that feel organic and adaptable.

And for all of Gibson’s gloomy prognoses about where things are headed, and how much worse they could become – you can sample his smart, dark, engaging worldview on Twitter, where he has the appropriate handle @GreatDismal – “The Peripheral” has a stubborn streak of hopefulness.

More than in any of his past novels, the future in “The Peripheral” is a moving target – and, as he makes a good case, regular people can move it to a better destination.