"Are you ready to be strong?"
The final phase of the Big Bad's plan, and the Cast's attempts to thwart it.
Allies, enemies, possibly a really cool stand-up fight with a lieutenant of the Big Bad, planning, arguing about plans, relationship issues coming to a head with all the stress and the "You're proposing to me 'cause we're gonna die!"
And the terrible omens of doom and the panicking citizens running for cover and the noncombatant supporting cast expressing their entirely understandable fears and...
Often a good idea to run this in a single longish session with the Season Finale, unless you really want to play on a cliffhanger, because most of the finale's runtime is given over to (a) dénouement and (b) extreme violence, so it's good to keep up that momentum.
Either way, this is the time for late-innings moves - like kidnapping PCs so rescuing them becomes part of the final session and they don't miss a few sessions chained to a wall.
And for the side of good, lost lore is found, allies return (possibly to die to prove the scariness of the Big Bad) and enemies betray their side, providing vital clues and real hope of victory to contrast with the otherwise relentless rush of bad news.
And any personal plots are resolved as well, at the best or worst possible moment. Love, heartbreak, uncertain power development, quests for souls, stuff like that.
And someone should deliver a rousing speech. Just not too many: "The other day, I gave an inspirational speech to the telephone repair man."
And just time for one last plot twist.
Example: Shake The Earth
The storm has come, and is surprisingly earthquake-y. And sea monster-y.