I’ve been on a slow boil for several years about why television, even when it’s great, isn’t always “fun.” It may be that great quality crowds “fun” off the screen — you react with passion, fascination, shock, awe, sadness and all kinds of other emotions to shows like “Breaking Bad,” “Mad Men” and “Game of Thrones,” but watching them isn’t “just” fun because it’s not meant to be.

Have I reached my quote marks quota for this review?

Anyway, television used to be fun and then it grew up. Or maybe we did. These days fun is such a rara avis in the medium that we forget how it used to be until a show like NBC’s “Crossbones” comes along to remind us. And when it does, on Friday night, you may find yourself wondering why other shows can’t be just fun to watch as well.

Why indeed? Well, for one thing, you need John Malkovich taking enormous bites out of the scenery playing Edward Teach, aka Blackbeard, whose beard is now white as he rules over life and illicit commerce on the island of New Providence in the Bahamas.

He may be a sea lion in winter, but he’s as ruthless and cunning as ever, so much so that he’s perfectly content for the British Navy to believe he’s been killed. But the guy who was supposed to have separated Blackbeard’s head from his neck, William Jagger (Julian Sands), knows better and is out to find his nemesis and either kill him or send him back to England for trial.

Tom Lowe (Richard Coyle) poses as a ship’s physician to guard an extremely useful chronometer, designed by a man named Frederick Nightingale (Henry Hereford). When the ship is attacked by pirates, Nightingale is mortally wounded, and Lowe fires a musket round into the chronometer so the pirates can’t get hold of it. If they do, they will be impossible to track on the high seas. Lowe also tries to burn the notebook containing instructions on how to build the gizmo. Some of the pages — written in code— survive, however, and Blackbeard wants them deciphered.

Lowe’s purported knowledge of the notebook’s contents enables him to keep his life and to be taken to Blackbeard’s island. Soon enough, though, Blackbeard comes to admire the young man, while, for his part, Lowe develops a grudging admiration for his captor as well. He develops something a bit warmer toward Kate (Claire Foy), the former Lady Balfour now branded a traitor by the English. She is married and quite loyal to her husband, James (Peter Stebbings), who is in a wheelchair most of the time and feels himself to be an inadequate husband.

The series was created and written by Neil Cross, who created the British series “Luther” and who has written for “Doctor Who.” NBC originally planned it as a midseason show but pushed it back to the summer, which is in some ways a better fit, except for the fact that it will air at the end of the night on Fridays, which means it will have a tough time finding an audience without time-shifting.

I hope otherwise, of course, if only because of Malkovich’s performance. This probably doesn’t rank with the most complex challenges of his distinguished stage and film career, but he’s clearly having fun with the role and, more to the point, with Cross’ sun-ripened dialogue. The writing on “Crossbones” is florid and extravagant, quite unlike dialogue on most TV shows. Malkovich might get the best lines, but Cross lays out a sumptuous banquet of words for all the central characters, including the mysterious agoraphobic Selima (Yasmine Al Masri), the equal-opportunity pirate Nenna (Tracy Ifeachor) and even Lowe’s dim-witted but loyal friend Fletch (Chris Perfetti).

Television has dipped a peg leg into the pirate waters in recent years, with the 2012 film “Treasure Island,” which aired on the SyFy channel, and more recently with Starz’s “Black Sails.” But where that series has its moments, “Crossbones” is great fun at every turn. It is filled with adventure on the high seas and sex and intrigue on dry land. And, yes, above all, it’s fun.