“A good mother would be able to let go,” June (Elisabeth Moss) said early during the final hour, confessing a failing in herself, from that perspective, before engineering what was surely the most cathartic moment the series has produced: The brutal execution of Commander Waterford (Joseph Fiennes) by the women that he had victimized in Gilead, led by June, who wore the remnants of that act on her face as she returned to cradle her baby.That moment felt almost like a relief, after an unsupervised one-on-one meeting between June and Waterford that, frankly, strained credibility, as the fourth season periodically has. Still, no one can quite match Moss — who flexed her creative muscles by directing three of this season’s 10 episodes — in the look-of-absolute-hatred department, creating a palpable sense of tension that she was going to find some ingenious way to kill Waterford right then and there.Instead, she managed to outwit him, arranging a prisoner exchange that returned him to Gilead, freed nearly two dozen women and still gave her and her friends the satisfaction of hunting him down like a wild animal.That scenario followed another questionable twist in the penultimate episode — a recurring issue since the program has advanced beyond Margaret Atwood’s book — with Waterford cooperating with his captors in order to secure his release. At first outraged by the prospect of her rapist walking free, June gathered herself to derail his bid for freedom, abetted by Commander Lawrence (Bradley Whitford) and Nick (Max Minghella).In what felt like a key line looking forward, Lawrence warned June that vengeance wouldn’t be enough for her. The changes she has experienced from her ordeal in Gilead have been evident throughout the season, among other things appearing to have seriously damaged her relationship with Luke (O-T Fagbenle), the big question being whether the rift is permanent or somehow salvageable.Already renewed for a fifth season, “The Handmaid’s Tale” has gradually morphed into a much different show than the one that became a cultural sensation — with red-cloaked women turning up at protests such as Supreme Court Justice Brett Kavanaugh’s confirmation hearings — and earned a best-drama Emmy, representing a breakthrough for Hulu (and indeed, streaming in general). When it looked like Waterford might actually get away with his scheme, June said bitterly that the world belongs to “weak men.” For those who have witnessed the horrors of Gilead over the past four seasons, there was surely a visceral thrill in seeing the triumph of strong and determined women, although where that leaves the series — and practically speaking, what its writers can muster for an encore after this — is anybody’s guess.