San Francisco — “Marco Polo,” the big-budget saga with occasional references to the real-life 13th century Italian merchant who hung out with Kublai Khan, is action-packed, compelling and filled with intrigue and sex … eventually.

And by “eventually,” I mean only after you slog through four slowly paced hourlong episodes filmed in semi-darkness, with a script filled with declamatory dialogue that does little to either humanize the story or help untangle the deceptively labyrinthine script. Once you do penetrate the mare’s nest of a plot, you realize you’ve probably seen enough of this kind of thing before to anticipate much of the action.

Six of the 10 episodes of the first season were made available to critics and for much of the time, I almost found myself wishing, for a change, that the network had sent fewer.

The series was created by John Fusco (“The Forbidden Kingdom”) and directed with somnambulant pacing by Dan Minahan, Joachim Ronning and Espen Sandberg.

It begins, of course, with the arrival of Marco (Lorenzo Richelmy), his father and uncle, in Mongolia, ruled by the great and powerful Kublai Khan (Benedict Wong). The elder Polos soon take off, leaving Marco to fend for himself as a guest of Khan, although, in truth, he is a prisoner.

There is upheaval both within the empire and beyond. Not only are the Chinese fighting to keep the Mongols at bay, but there is treachery among the Mongol tribes, including the one headed by Khan’s younger brother, who has designs on Khan’s expansive throne. In China, the aged emperor is on his death bed, with only an infant son as an heir, opening an opportunity for his scheming chancellor, Sidao (Chin Han), to claim power after the emperor’s death. He blackmails his sister, Mei Lin (Olivia Cheng), into becoming a concubine in Khan’s harem in order to keep tabs on what the Mongols are up to. Basically, he’s the Song Dynasty equivalent of Lord Baelish in “Game of Thrones.”

Through all of this, you may find yourself asking, “Where’s Marco?” Well, he’s there and sometimes even present in the thick of things, but the character is a somewhat uninteresting cypher. He takes kung fu lessons from the blind Hundred Eyes (Tom Wu), smokes some sort of Mongolian peyote and imagines himself in the center of an orgy, trails the mysterious Blue Princess (Zhu Zhu) around trying to figure out where she goes at night, and gradually insinuates himself in Khan’s good graces.

But he’s not that interesting, which may have something to do with Richelmy, who certainly looks the part of a swarthy young hero but is rather passionless, even when Marco is forced to decide punishment for his father and uncle’s transgressions against Khan and when Khan is attacked by would-be assassins.

You can’t really blame Richelmy as much as Fusco and his band of merry directors, all of whom seem to be straining for the longest time against the temptation to turn “Marco Polo” into a martial arts series, either of the Bruce Lee variety or the “Crouching Tiger, Hidden Dragon” ilk.

By the fifth episode, fortunately, Fusco et al give in and “Marco Polo” rocks with lots of action, much of it in the “Tiger/Dragon” slo-mo style. At this point, “Marco Polo” breaks loose from its dingy lethargy.

Although even Richelmy isn’t bad, just irrelevant, several actors pump energy into “Marco Polo” to keep it afloat, beginning with the endearing first family of Mongolia, Benedict Wong and Joan Chen. Wong plays Kublai like a 13th century Mongol Henry VIII, commanding our focus in almost every scene he’s in, while Chen brings depth, majesty and welcome nuance to the role of the Empress Chabi. Thanks to Chen, the Empress is the most interesting character in the whole shebang.

In supporting roles, Australian actor Remy Hii is perfect as Khan’s son and heir, who has been raised in China and is now trying to be the man his father wants him to be. Tom Wu is mesmerizing as the all-seeing blind martial arts master Hundred Eyes, Chin Han a picture of unadulterated evil ambition as chancellor Sidao, and Mahesh Jadu is quite convincing as the not entirely trustworthy Ahmad.

The opening credit sequence for the series evokes that of “Game of Thrones,” but with flowing ink creating images such as bodies hanging on pikes, an attacking eagle and, for some completely unknown reason, a replica of Caravaggio’s self-portrait as the head of Goliath in his painting “David With the Head of Goliath.”

But this isn’t “Game of Thrones,” and not only because it’s about 13th-century Mongolia and not seven mythical kingdoms. There is a lot of violence in it and a whole lot of nudity, and there are superb performances, all of which are undermined by ponderously self-important writing and direction. The fifth and sixth episodes suggest that “Marco Polo” may belatedly get over itself in the home stretch, which may be OK since this is a streamed show with multiple episodes available at once. But you still have to give viewers a compelling reason to keep going from the get-go.