Chalk up 1971’s Unman, Wittering and Zigo as a weird choice of title, for it sounds more like the name of a law firm than a feature film. As it happens, the film brings a thriller.

Chantry School for Boys sits on the coast of England. When Schoolmaster Pelham dies, John Ebony (David Hemmings) takes his place.

When he arrives with wife Sylvia (Carolyn Seymour), Ebony proves idealistic and eager to teach. However, he encounters resistance from his students and gradually starts to believe they had something to do with his predecessor’s demise.

Many movies adapt stage productions, but Unman comes from an unusual source. It brings a radio play to the big screen.

I’m sure Unman doesn’t sit alone in that category, but I’d feel hard-pressed to come up with another movie taken from a production that originated on the old wireless. At least it lacks the constrictions that come with stage shows.

Those tend to feel limited since the source needed to figure out how to work within limited sets. A radio play allows for virtually limitless ambition.

Not that Unman shoots for the moon. Given its subject matter, it sticks with pretty limited locations and scope.

That makes sense given the story at hand. A psychological thriller, Unman doesn’t need a lot of locations to work.

Indeed, a sense of claustrophobia helps the tale. As the movie proceeds, we get more involved in the potential mystery.

As Unman launches, it feels like it’ll deliver an inspirational tale in the vein of To Sir, With Love. We see eager beaver Ebony as he welcomes the chance to educate his rambunctious young pupils.

Of course, Ebony encounters insolence that initially frustrates him. If Unman followed the To Sir model, we would see how Ebony learns to connect with the kids and win them over to his side.

Instead, Unman follows a more insidious path. Rather than simply annoy Ebony with insolence, the students intimidate him with claims that they murdered Pelham.

That takes Unman into psychological thriller territory, and it does pretty well in that regard. Unlike many in the genre, the film manages to sustain mystery much of its running time.

Given how many films of this sort telegraph the truth, that becomes a notable accomplishment. For most of Unman, we genuinely don’t know if the kids actually killed Pelham or if they just tell Ebony this to get him to obey their wishes.

And then there’s “Zigo”. The film’s title refers to the final three students on the class’s alphabetical roster, with Zigo a perpetually – and mysteriously – absent student.

Will Zigo play a substantial role in all of this? Perhaps, but the movie doesn’t toy with us in that regard, so expect that to become another of the film’s secrets.

Unman can feel a little long for the story it tells, and the scenes with Ebony’s wife can feel a bit superfluous. While these help depict his mental deterioration to a degree – and she offers another potential threat to Ebony if his students target her - she nonetheless mostly seems unnecessary and Sylvia feels as though she exists to give the tale its sole female character.

Nonetheless, that becomes a small criticism of this largely engaging thriller. Subtle and haunting, Unman turns into a pretty effective tale.

Unman, Wittering and Zigo appears in an aspect ratio of approximately 1.85:1 on this Blu-ray Disc. The movie came with a fine transfer.

Sharpness appeared clear and concise. On occasion some shots looked slightly soft or hazy, but these instances did not occur frequently, and I suspect they reflected the source photography. Instead, the majority of the film was crisp and detailed.

No issues with jagged edges or shimmering materialized, and edge enhancement was minimal at worst. Source flaws stayed absent, so this was a clean image without any noticeable print defects.

Unman featured a fairly low-key palette and brought appealing colors within those constrictions. The tones seemed well-rendered given the movie’s restrained ambitions.

Black levels appeared deep and dense, and shadow detail also was clear and without excessive darkness. Across the board, this became a solid presentation.

The LPCM monaural audio of Unman held up fairly well over the last 52 years. Speech came across as reasonably warm and natural, with no issues of edginess or intelligibility along the way.

Effects appeared a bit thin, and they didn’t suffer from any distortion or other problems. Music also was reasonably bright and rich, with adequate range. For a monaural soundtrack from 1971, Unman seemed satisfying.

As we shift to extras, we launch with an audio commentary from film historians Sean Hogan and Kim Newman. Both sit together for this running, screen-specific look at the source radio play and its adaptation, cast and crew, genre domains, the British school system of the era and their own experiences, and their thoughts about the film.

Newman dominates. Though Hogan gets in occasional remarks, much of the time he feels like Ed McMahon to Newman’s Johnny Carson, as Hogan often does little more than laugh and exclaim “yes!”

Despite that, this becomes a decent commentary. We learn little about production specifics, but we get enough related to the property, the genre and those involved to make this a moderately useful track.

Two featurettes follow, and An Unruly Education spans 25 minutes, 45 seconds. It provides notes from critic/broadcaster/cultural historian Dr. Matthew Sweet.

“Education” covers how Unman represented the culture of its era, notes about the play’s writer and his works, aspects of the film and changes from the source, and various reflections. Some of this repeats from the commentary, but Sweet nonetheless offers a nice overview.

Unman, Lipstrob & Terhew + Mrs. Ebony lasts 30 minutes, 13 seconds. Here we get info from actors Michael Cashman, Michael Howe, James Wardroper and Carolyn Seymour.

They tell us about their characters as well as their experiences during the shoot. They relate some reasonably interesting memories.

We also find the 1958 Radio Play on which the movie comes based. It runs one hour, 13 minutes, one second.

With no score and minimal effects, the radio version seems stark by comparison with the film, and it acts more as a morality play – or lack thereof, as it accentuates the various characters’ absence of ethics. The radio Unman also feels less like a mystery.

This creates an interesting tale, though one that seems more heavy-handed than the film. The movie adaptation proves more nimble.

In addition to the film’s trailer, we finish with an Image Gallery. It offers 139 stills that mix publicity elements, shots from the movie and behind the scenes photos. Though that becomes a generous number of pictures, they tend to feel less than compelling much of the time.

While not on the level of classic thrillers, Unman, Witting and Zigo nonetheless delivers a pretty solid psychological journey. It maintains a noteworthy level of subtlety that ensures it never telegraphs its elements to the audience. The Blu-ray comes with appealing visuals, acceptable audio and a mix of bonus features. This winds up as an effective journey.