Ryan, a CIA analyst whose expertise in the financial sector makes him good at looking for terrorists by following the money that funds them, thinks he has found signs of a major plot mounted by a shadowy terrorist called Suleiman. When he forces the hand of his superiors in freezing the transactions, he finds himself called on the carpet for exceeding authority as well as tipping Suleiman that someone's watching. His supervisor enlists him in the project to find out and thwart the plot, putting Ryan more on the operational side of things than he has been before. Although he served in combat as a Marine, the kind of murky, ghost-hunting game played by the CIA leaves him a lot more unsure of himself than he prefers. Suleiman's complex plot keeps the agents on their back feet and trying to guess his next move.
Krasinksi came to fame by starring as the mild-mannered everyman Jim Halpert in The Office, and he brings much of that same regular-guy low-key energy to his portrayal of Ryan. It's effective, as Clancy initially conceived of Ryan as much more of a desk man a little out of his depth when he was in the field. Krasinksi's Ryan is competent, intelligent and driven but is by no means one of the hard-charging hoo-rah operatives that swagger in the background of the show. He's easily the highlight of the show as well as its star, even though Wendell Pierce as his boss James Greer and Dina Shihabi as Suleiman's wife Hanin also stand out in important roles.
The first season's story is uneven as it swirls around its cast, though. Suleiman is a pretty stock character and his ultimate plot seems to owe a little too much to Wile E. Coyote for someone as clever as he's supposed to be. Side plots like one involving a drone operator waste time. While Ryan's burgeoning romance with Cathy Mueller gives a couple of good windows to develop his character and show what's inside, it doesn't really do much for her except show us why she might be endangered as Suleiman's plot enters its endgame.
As his novels continued and expanded, Clancy turned Ryan from Clark Kent to Superman, as well as a lot less interesting. By the time the 1990s arrived, the major obstacle to Ryan's thwarting of whatever nefarious plot he faced was Clancy's need to fill pages and take arms against whatever political threat he saw facing the United States. But it was when Ryan was less sure of himself and wielded less power that he was a more interesting character, relying more on the authority of his knowledge and insight than his position and paladin-like personal honor. If Krasinski continues to project the same Regular Guy persona as Ryan, and the scriptwriters develop more and borrow less, Tom Clancy's Jack Ryan might navigate the gap where Clancy himself faltered, and stay out of the dead-end swamp of the Bestseller Bloat Uberman that claims too many interesting characters.
Lead bounty hunter "Dutch" (Hanna John-Kamen) begins the season in "the Green," a kind of Matrix-ish space accessed by pools of green goo. That same goo has transformed thousands of humans into Hullen, a sort of super-soldier who has secretly worked to undermine the human governments preparing for a takeover by Aneela (also John-Kamen). At the end of Season 3 Dutch joined Aneela to enter the Green and fight the Lady, a being who lives inside it and who is behind the actual invasion plans. Left outside are her partners, John and D'av Jaqobis (Alan Ashmore and Luke Macfarlane), suddenly caring for their previous enemy Delle Seyah Kendry, (Mayko Nguyen) now a Hullen and very pregnant with a child Aneela had implanted in her.
The team eventually reunites and plots with the remnants of their old bounty-hunter service and other fighters to counter the Lady's machinations. Dutch will have to learn more of her own history and that she shares with Aneela, while D'av must deal with the realities of fatherhood to a very different young man. They're racing against time, because while Dutch learned what she needs to defeat the Lady, they'll have to get it ready before the Lady overwhelms Aneela and escapes the Green.
Part of Killjoys' problem beginning with the last season was its complete lack of sense. Having established the main threat of invasion by an armada of fast-healing, fast-acting, super-strong alien-controlled humans, it meandered through several dead-end sequences that grabbed whole episodes worth of time and did nothing to aim our protagonists at the threat. It ended in a hurry, trying to catch too many threads up at once to show any of them clearly. The same problem continues through Season 4, with the additional issue of spending 10 episodes trying to keep the Lady inside the Green, only to let her out in the final episode cliffhanger.
John-Kamen and Macfarlane continue to offer excellent performances in service of a plot that makes them more exhibits in a display than pieces of a story. Add Kelly McCormack's turn as Zephyr Vos to that roster, but as in the other two cases the top-level acting is just there, rather than resting on any real narrative foundation.
Season 5's 10 episodes air in 2019, and if Killjoys is to succeed at coherence it will take every one of the 420 minutes of airtime to put what we've already seen in enough context to give the resolution any more meaning than it might have had if the whole story was told in a two-hour movie.