Thanksgiving is a couple of weeks off, but we should be grateful for the character-actor bounty that has arrived well before the holiday.

Last week, HBO gave us the prickly, perceptive “Olive Kitteridge,” which was an excellent showcase for Frances McDormand, Bill Murray, Richard Jenkins, Jesse Plemons and Zoe Kazan, among others.

This week, two polished U.K. spy thrillers arrive in the U.S, and though the drama airing on PBS is almost ridiculously loaded with high-wattage talent, both programs are worth a look. Neither surpasses the high-water mark left by the original “State of Play” miniseries, which may well be the gold standard in the U.K. spy-thriller category. That said, PBS’ “Worricker” and BBC America’s “The Game” boast enough charms and character-driven set pieces to offset their occasional rough spots (and “Worricker” supplies Nighy with even more screen time than he had in “State of Play”).

“The Game” has a lot in common with “The Americans,” if you subtract the central marriage metaphor and set the show in the beleaguered Britain of the early ’70s instead of the Reagan era in the U.S. The central conceit involves a young espionage agent, Joe Lambe (Tom Hughes), whose individual quest for revenge becomes intertwined in a high-stakes Cold War battle, and though it’s not a dealbreaker, the personal-vengeance part of the plot is the weakest aspect of this otherwise well-calibrated spy series.

In the first two episodes of the six-part first season of “The Game,” we learn little of interest about the relationship that drives Joe’s vendetta; so little time is spent on a shadowy woman in Joe’s past that she remains a plot point and never comes alive a person. Joe himself is also a bit of a cipher; spies are generally trained to be remote, of course, but “The Americans” does a better job of giving the audience clues about its characters’ emotional dilemmas.

Joe may be no Philip Jennings, but it’s easy to be absorbed by the rain-slicked world around the cagey lead character of “The Game.” The drama excels in the realms of atmosphere, tension and mood, and these are the vital things that a spy drama can’t get wrong. “The Game” also does a terrific job of evoking the strained, washed-out Britain of the ’70s; the clothes, the decor and even the eyeglasses look exactly right, and the old-school reel-to-reel tape recorders and clunky equipment remind us that one of the most high-stakes conflicts in human history relied on balky, unreliable technology.

At its best, “The Game” keeps efficiently moving forward while evoking the sense of pessimistic stalemate that often envelops good spy novels and films. Whatever side they’re on, many spies eventually realize that all their moves and countermoves more or less cancel each other out and that all their high-risk operations may add up to nothing in the grand scheme of things. But the roster of savvy MI-5 agents Joe works with keep going, partly out of a sense of duty to their country, and partly because they seem to have realized that no other profession would allow for so much personal eccentricity and provide so much unpredictable adventure.

Brian Cox plays the venerable head of MI-5 in “The Game,” and his air of gruff, intelligent weariness is always a great pleasure to behold. Because no one is supposed to know the name of the head of MI-5, the staff calls him “Daddy,” which is both weird and kind of appropriate, in that Daddy carries with him an air of incontrovertible authority and canny judgment. Cox is one of the great, grizzled lions of the acting profession, and in “The Game,” he once again functions the charismatic presence around which everything revolves.

Other standouts in the cast include Steven Mackintosh of “Luther,” who somehow makes his sociopathic character compelling through sheer force of will, and Paul Ritter as a slick, ambitious upper-class type who is reduced to sniveling fear by his terrifying mother. Victoria Hamilton and Jonathan Aris give wonderful dimension to a married MI-5 couple whose bond is one of the few solid, sweet things in a world that mostly provides disappointment for its characters. Aris is particularly good at providing moments of dry comic relief, and it should be noted that “The Game” is not one of those spy dramas that takes itself so seriously that moments of pulse-pounding adventure get lost in the shuffle.

Don’t look for the two “Worricker” films, airing Nov. 9 and Nov. 16, to provide much in the way of action, unless watching Bill Nighy read a book on the beach gives you an adrenaline rush (and it might). With these two TV movies, which are sequels to the smart political thriller “Page Eight,” writer/director David Hare has two clear agendas: To flog a set of talking points regarding the post-9/11 security state, and to give his actors, especially Nighy, a lot of meaty scenes.

Hare jams these two agendas together without much regard for the finer points of plotting, and the backgrounds and histories of his characters come off as similarly slapdash at times. What he really wants is to get two whip-smart characters into the same room so they can fire razor-sharp verbal salvos at one another, and these charged pairings are usually so satisfying that you’re willing to forgive the awkwardness or corner-cutting that brought them about. Just be prepared for the fact that the middle of each film goes squishy, story-wise, because Hare wants to bring about confrontations, not necessarily lay out their context with crystal clarity.

What can you say about Nighy except that he’s peerless at Nighy-ing? His frisky charisma enlivens every scene he’s in, and he’s so (correctly) confident about what his presence brings that he is often quite still and considered in his physical performance. He walks with a languid, slanted lope; he drapes his sinuous form lightly on furniture; one pause or raised eyebrow can speak volumes. Nighy going small, performance-wise, does not diminish our interest in the quietly aggrieved spymaster Johnny Worricker; it only makes us more interested in what he’s not saying and what he’s thinking, and his stillness makes the character’s rare outbursts all the more effective. Faced with the opportunity to chew scenery, Nighy relies instead on quiet wit, presence and the calm mastery of craft.

On balance, this was certainly the right approach for Nighy’s scenes with Christopher Walken, who brings his usual engaging weirdness to the role of a shady espionage operative that Worricker stumbles across during his enforced retirement. You’d think enlisting both Walken and Nighy would be enough for Hare, but no: A list of all the actors who get screen time in the two Worricker films is almost overwhelming (and a commentary on how few mid-budget, character-driven films are being made these days).

Winona Ryder, Ralph Fiennes, Rupert Graves, Felicity Jones, Malik Yoba, Judy Davis, Rupert Graves, Olivia Williams and Helena Bonham Carter all get respectable amounts of screen time in one or both of the “Worricker” films. This is the kind of project in which the wonderful Dylan Baker turns up for little more than a cameo. When Hare calls, actors come running, and why wouldn’t they? His verbal buffet of tirades, monologues and witty rejoinders is pretty tempting. (And by the way, you don’t need to have seen “Page Eight” to enjoy these two installments.)

In the “Worricker” trilogy, Hare has points he wants to make about the shady laundering of money in the global economy, war profiteering and the ways in which the press, intelligence agencies and governments collude and collide. Some of those points are well taken, but Hare tends to make them again and again, and on occasion, the characters sound as if they’re repeating talking points ginned up at a cocktail party attended by London’s chattering classes.

But honestly, it’s hard to care about any of that, because these films generally use their stellar array of actors well, and the cast energetically wolfs down the red meat Hare gives them. Fiennes is particularly great at playing a chilly brand of arrogant condescension, and Williams and Davis display alluring spikiness in their roles as powerful, cynical shot-callers. Ryder’s role is a bit overwritten and melodramatic, but her wry, fiery performance made me wish we saw her on screen more often. All in all, this is an entertaining and intelligent stew, even if bits of it are a tad overcooked.

Perhaps the “Worricker” films aren’t really spy thrillers at all: They also belong to a genre I hereby dub “the Magical Englishman” (who is sometimes allowed to be a Scotsman). Worricker, we are led to believe, is the Last Honest Man, the one who really cares about the right things and has the most selfless values and is willing to sacrifice everything in order to fight the good fight. What are those values and beliefs, exactly? Well, they’re sort of humanist, but once again, everything goes squishy and ill-defined beyond a certain point. The Magical Englishman is an idea more than anything else — a hero, a bit of wish-fulfillment or a double-edged myth, depending on your point of view. Johnny Worricker may as well be the lead character of “Doctor Who,” except he fights with inconvenient documents and safe houses instead of a sonic screwdriver and a TARDIS.

The question of whether Worricker, or Joe Lambe (“The Game”), for that matter, are working within — or trying to change — a system that is hopelessly outmatched or fatally compromised is not something that either of these shows delves into all that deeply. These are slick entertainments, in the end, and but at least they occasionally hint at greater depths.

“The Game” airs Wednesday at 10 p.m. ET on BBC America.
Masterpiece’s “Worricker: Turks and Caicos” airs Nov. 9 on PBS.
“Worricker: Salting the Battlefield” airs Nov. 16 on PBS.
Some PBS stations will air “Page Eight” on Thursday, Nov. 6.
Check local listings for times.