The forecast is bleak in “Maze Runner: The Scorch Trials” (Fox).

Picking up where 2014’s “The Maze Runner” left off, the relentless pacing and nonstop action leave little time to decipher the convoluted yet unsubstantial plot, which is probably a good thing.

When our youthful heroes are not too busy running, they espouse the virtues of loyal friendship and self-sacrifice. Unfortunately, most of their adult counterparts are evil and untrustworthy, which seems to be de rigueur for the young-adult genre these days.

Like its predecessor, “The Scorch Trials” is essentially a mash-up of “The Hunger Games” and “Divergent” — this time with a good dose of “Mad Max” and “Night of the Living Dead” added to darken the formula still further.

The narrative centers on a band of intrepid youth known as “Gladers,” who have escaped the mysterious maze of the title. The vast labyrinth turns out to have been an elaborate initiation exercise organized by the so-called Creators.

The Gladers are now lab rats within the aptly-named “World in Catastrophe: Killzone Experiment Department” (WCKD).

The Gladers have something the Creators desperately need: their blood. It seems they have a natural immunity to the vicious plague that has devastated the world beyond the laboratory.

This so-called “flare” virus, named after the solar flare that scorched the Earth and destroyed everything in sight, turns people into flesh-eating undead types known as “Cranks.”

Unwilling to be bled dry like their peers, the Gladers escape and take their chances outside in “The Scorch.” There they hope to locate, and unite with, a group of resistance fighters whose exploits have become mythical.

Viewers of faith will note some vaguely Christian symbolism in “The Scorch Trials.” This ranges from the life-giving quality of the Gladers’ blood to the name of the aforementioned resistance force, “The Right Hand.” Yet these hints at spirituality represent mere incidental curiosities along the path of a largely unrewarding slog through a grim, terror-ridden future.

The film contains relentless, often intense violence, including torture, gory images, drug use and some profane and crude language. (A-III, PG-13).