(Warning: Spoilers... nothing less than a year old though.)
On a recent run, I began to tell a friend of mine about The Queen's Gambit, an excellent 7-episode miniseries on Netflix about a female chess player who rises through the ranks of the competitive chess world. He asked if it would go on to future seasons, and I honestly didn't know, but I said that I felt comfortable with how it wrapped up, and that I felt they'd given it enough closure to call it a wrap, but hadn't burned any bridges to continuing for another season if they decided they wanted to. I said that I enjoy when shows either end with a really nice, concise, tied-off finale or with the kind of cliffhanger that leaves it open to interpretation in an intriguing way that holds a sense of closure of its own.
I proceeded to use the example of Season 1 of The OA, in which a woman named Prairie Johnson, who may be crazy or may be telling the fantastical truth, leads a disparate group of high schoolers (and one sympathetic teacher) to an important moment in the season finale that saves lives. Throughout the season, we wonder whether the fantastical story that the woman tells this group of followers has any real credence, or if she's actually just insane. Whatever the truth, we watch as she teaches them all to perform very artistic dance movements that are supposed to hold power when performed together: ranging from healing to teleportation. We only see evidence of these powers in her recounting of a story of captivity, and so we can't - as an audience - be sure whether this is genuine or not. The final episode of Season 1 doesn't necessarily answer these questions for us, but it does rekindle a sense of hope that she may not just be crazy... a concern that her group of followers had begun to give in to as the season progressed: when a school shooter threatens students in the cafeteria, the students stand up from under their tables and - joined by the teacher who has run back into the school to join them - proceed to perform the moves that they had learned. Nothing observably magical happens: they just distract the shooter long enough for a cafeteria worker to tackle him. The final gunshot that fires off in this moment goes through a window and hits none other than our protagonist, who has arrived just in time to see her band of devotees perform the moves that she had trained them to perform...