“Mary Kills People” is a smart, entertaining series that understands, on a core level, that nobody really wants to watch a TV show about medically assisted suicide. Use of that phrase so early in this review may send some running for the exits, but that would be a mistake. “Mary Kills People” is an energetic, savvy program that combines elements of crime thrillers, medical soaps, and propulsive character drama, employing all those recognizable forms to illuminate the complexity of the knotty issues at its core.

Anchored by a charismatic performance from star Caroline Dhavernas, “Mary Kills People,” a Canadian import, resembles its lead character’s specially prepared doses of life-ending medication: It combines the dark stuff with a dollop of fizzy champagne. With a fraction of the resources of most American shows but a surfeit of ideas and frisky energy, this Lifetime drama supplies one of the most impressive debuts of the year.

The show itself is merciful; it doesn’t take long to go about its business. In this era of episodes of television that drift in maddening ways and seasons that often seem too long at a mere 10 or 13 episodes, “Mary Kills People” operates with a brisk Canadian efficiency. Its first season consists of six episodes, none of which is longer than 45 minutes. It’s easy to forgive a few patchy subplots and one or two generic bits of casting, given that “Mary” marches forward with a sense of purpose and economy that shows with 10 times its budget would do well to emulate.

Dhavernas, a versatile actor who brought a similar steely sympathy to her “Hannibal” character, plays Mary Harris, an ER doctor with a thriving side business. For a fee, she and her partner, Des (Richard Short), help people with terminal illnesses end their lives. Given that the activities of Mary and Des, an acerbic former plastic surgeon who lost his medical license, aren’t exactly legal, they are forced to operate on the fringes, which they rather enjoy.

Part of their pitch is that their services cost half of what it would take to participate legally in “death tourism” in Switzerland, where ending one’s life with medical assistance is possible — for a price. But it quickly becomes clear that Des and especially Mary don’t help people die primarily for the money. There’s certainly a lot more percolating inside Mary, who clearly enjoys the injection of risk that her side job brings to her otherwise normal, suburban-mom life.

A core acknowledgment of “Mary Kills People” is something that our death-averse culture rarely addresses, outside of gangster movies and other fantastical stories: There’s something deeply alluring about the having — or being near someone with — the power of life and death. An individual’s imminent demise is, of course, usually wrenching, but it can also add excitement and importance to the lives of those in the vicinity of that death, even among those who have a healthy sense of right and wrong.

But there are many grey areas when it comes to helping a suffering person end his or her life, something that those with terminal loved ones and medical professionals know all too well. In hospital rooms and in homes crammed with medical supplies and prescriptions, the definition of compassion can change on an hourly basis. Without ever lapsing into grimness or dour melancholy, “Mary” acknowledges the murky, thrilling and gut-wrenching power of illness, death and suffering. The show also makes it seem natural that these kinds of moral puzzles and questions would attract the attention of a curious, thoughtful adult, especially one with an addiction to a very specific kind of power.

Though its lead characters are very different people, “Mary Kills People” is a little reminiscent of the first season of “Orphan Black”; both are low-budget, lively productions that use the trappings of medical thrillers to explore issues that, in the wrong hands, could have been exploitative or sloppily rendered. It’s worth pointing out that the creator of “Mary Kills People,” Tara Armstrong, as well the show’s sole director, Holly Dale, and most of its writers, are female. That Mary could be a thoughtful, caring doctor and friend, and also a calculating, self-destructive woman whose taste for danger damages others, is taken for granted by the show’s creative team. There are no didactic tendencies in “Mary Kills People” — there simply isn’t time for them — but the idea that a woman would be interested in matters of agency, power and responsibility is simply baked into the worldview of the drama.

Self-deprecating and often surprisingly self-aware, Mary is essentially obsessed with control: She thinks patients should be allowed choices when it comes to their deaths, and she also mistakenly believes she can divert or limit the chaos that results when the wrong people find out about her side hustle, and that begins to happen when some end-of-life scenarios go sideways (sometimes in quite amusing ways). When it comes to her patients’ dilemmas and her own day-to-day life, Mary likes to live on the edge, and yet she never comes off as thoughtless or unfeeling. She’s just got much more baggage — and more of an appetite for electric risk — than her patients, or the cops on her trail, realize.

There are a few elements of the show that never fully gel: Mary’s flirtation with a stolid male character who poses a threat to her business is less interesting than anything involving the cynical and entertaining Des, and her teenage daughter’s plots regularly threaten to fall into predictable ruts. But these are minor quibbles. A bigger complaint is that the scenes of Mary and Des with their patients are often so good — insightful, warm, and even funny about death and suffering — that it’s easy to wish for a spinoff that’s just scenes of them chatting with patients while preparing that unique cocktail.

All in all, “Mary Kills People” pulls off a melding of tones — comedic, dramatic, and philosophical — that seems next to impossible, until you witness the slippery doctor with the great bedside manner pulling it off.