NEW YORK (CNS) — Atmosphere trumps substance in the fantasy adventure "Shadow and Bone." Sprawling, complex and tinged by problematic details, the eight-episode series is currently streaming on Netflix.

Based on two sets of novels by Leigh Bardugo, and created by Eric Heisserer, the program is set in an imaginary version of late 19th- or early 20th-century Tsarist Russia.

There, many people are endowed with superhuman gifts, including the ability to summon fire and wind. But the realm is divided by a region of darkness, known as the Fold, inhabited by predatory raptors called Volcra.

While on a perilous journey through this area, Alina Starkov (Jessie Mei Li), a military cartographer, discovers a previously unsuspected ability of her own that makes her both a potential hero and a target for power-hungry villains.

Ordered to refine her newfound faculty under the patronage of powerful Gen. Kirigan (Ben Barnes), Alina is compelled to separate from her best friend since childhood, fellow orphan Malyen "Mal" Oretsev (Archie Renaux). Their interrupted relationship teeters back and forth on the brink of romance.

Among those angling to capitalize on Alina's capability is a trio of shady, though not really evil, underworld characters: hard-driving gang leader Kaz Brekker (Freddy Carter) and his two sidekicks, mysterious Inej (Amita Suman), who can appear and disappear at will, and fun-loving sharpshooter Jesper (Kit Young).

It takes a while to set all these moving parts in motion. But once fully underway, the proceedings move along at a good clip, aided by lavish production values and a charismatic performance from Carter. While diverting, however, the show lacks any consistent thematic takeaways, at least during the first three installments reviewed.

Though older teens are clearly a target audience for the production, its ambiguous treatment of faith — along with more incidental elements — will be of concern to parents.

One of Alina's most frequent exclamations is "Saints!" and icons put in an occasional appearance, in at least one case as a treasured memento. But The Apparat (Kevin Eldon) — the single explicitly religious figure who crops up, dressed in a modified monk's habit — comes off as, at best, smarmy, at worst, secretly wicked.

While meditating on whether her unique talent makes her the prophesied saint who would free the land of the Fold and its dangers, moreover, Alina cast doubt on the idea as typical of all the beliefs she and Mal have always rejected. Whether this represents a science-based denial of religious belief per se, however, remains unclear.

"Shadow and Bone" includes some gory violence, a glimpse of rear female nudity and a prostitution theme. Additionally, one of the denizens of the demimonde Kaz inhabits is a female impersonator called Poppy (Micah Holmes) while another minor character expresses her openness to the idea of a lesbian relationship.

The dialogue includes only a few mild oaths and a touch of crude language. And, in its initial stages at least, Alina and Mal's bond is expressed by nothing racier than holding hands.

Yet the program, which is rated TV-14 — parents strongly cautioned, is certainly safest for adults. They'll likely find it entertaining on the surface though lacking in depth and lasting impact.