If any one word can retroactively demolish the quality of a great film, it’s “sequel.”

Have you ever watched a movie and felt like it was shorter than its runtime? There’s more to a great film than can be communicated in an hour and forty-five minutes. It’s natural for us to crave more from stories that we love - and that’s where the sequel comes in. But a bad sequel, especially one that follows a masterpiece, can feel like a slap in the face.

“But no one expects a sequel to be great,” I hear you pointing out; “Everyone knows that none of the Transformers sequels will be as good as the first one.”

Well, first of all, none of the Transformers sequels will be even as good as the grime I cleaned out from my keyboard before I sat down to write. But as far as the state of sequels is concerned, I must say, au contraire: some of the best movies to ever grace the silver screen are second installments that show up their predecessors. These are often sequels to already-great movies, so such a sparkling follow-up film is doubly rare, but far from impossible.

In fact, it boils down to one simple sentence: it’s not a rehash of the first film.

The most refreshing sequels, oddly enough, differentiate themselves from their predecessors. They keep elements about the first that people enjoyed, but they continue the story by giving their characters some new kind of challenge to overcome. The best sequels pit the same characters against a different challenge in a new context.

Terminator 2: Judgement Day took an already fascinating premise (time-travelling killer robots) and ran with it in a wildly different direction than did the original Terminator. The story now focuses on John Connor, who we don’t even see outside of a photograph in the first installment, and adds several new variables to the mix: Sarah’s mistrust of the T-800; the new, improved, and terrifying antagonist T-1000; the T-800’s apparent acclimation to human mannerisms and emotion; and the end-goal of stopping Judgement Day. There’s a reason that the next three times that Arnie was back weren’t nearly as successful. (Hint: among other things, they didn’t do this properly.)

In addition to placing the characters in a new situation with new difficulties to overcome, a great sequel keeps its characters consistent. Not the same, but consistent. Relatable characters remain true to their roots, but also experience believable change in a way that makes sense. Judgement Day also did this brilliantly: another variable changing up the second installment’s beat sheet is Sarah’s new status as a resident warrior goddess. While the first Terminator saw her running and cowering in fear from her automaton assassin, T2 showcased the same sentimental, dedicated Sarah Connor as a world-worn gun-toting mother-of-all-mothers. However, there’s another excellent sequel that perfected this transformation.

Ellen Ripley was the second-coolest thing to come out of Ridley Scott’s 1979 slow-burning horror mainstay Alien (after the Xenomorph, of course). She takes charge in the original; her instincts are spot-on, and, of course, she had the ingenuity to survive a space-boat ride with the spawn of Satan. But the Ripley in James Cameron’s combat-thriller follow-up rides tanks through walls and carries a helpless child in one hand and a flamethrower in the other. The wit that carries her through the first ordeal also keeps her through this new chaos, but her first encounter of the third kind has left her resolute in her goal to wipe out the xenomorph species.

Aliens, like any great second installment, also builds constructively on the foundational lore of the original. One distant, dusty, uninhabited planet became a distant, dusty, uninhabited crime scene; one terrifying, acid-blooded killing machine became an army of acid-blooded killing machines with a hierarchy and a queen. The scope of the world in which Ripley exists widened by that much, and audiences ate it up. As well, one more show-stealing sequel was able to do this properly.

The tepid bathwater that is the Star Wars prequels have proven that George Lucas’ brainchild is invulnerable enough to have become a permanent tentpole of pop culture. The first act of the space opera didn’t have to establish the worlds which existed “a long time ago, in a galaxy far, far away;” these worlds simply were. And we saw even more of that expansive, livable universe in just that way in The Empire Strikes Back. This sequel also goes light-years beyond building upon the lore straight to turning the tides of the franchise with five simple words: “No, I am your father.” Unforgettable.

People don’t love stories. People love good stories. People love falling in love with the hero and walking with him on his journey of discovery; people love seeing themselves in the tempest-tost protagonist. Revisiting a favorite franchise is like coming back to an old friend, eager to be regaled with their latest exploits and revelations.

While the market is flooded with cash-grab follow-up films, a return to quality is in order. A renaissance is coming. A good sequel is an entertaining afternoon with old friends, and a love letter to a loyal fanbase. It says to you, “I love you;” and in return, you say, “I know.”