Picking up from the end of Stairway To Heaven, when Dean attacked Gadreel - who'd come to The Bunker offering his help to usurp Metatron - this episode was non-stop action all the way through to the brutal climax.
Dean is quickly restrained and imprisoned, while Cas and Gadreel head back to Heaven - using the classic Wookie play from Star Wars. They are looking to sever Metatron's connection to the Angel Tablet, which is giving him God-like powers.
Sam, meanwhile, heads out to follow up on a viral video of Metatron raising a woman from the dead.
Having won all the angels back to his side, Metatron has now descended to Earth, disguised as a homeless man called Marv, to begin a grassroots movement proclaiming him as a new messiah, by performing miracles.
I have to be honest, this sudden switch by Metatron isn't clearly explained. Up to this point he hasn't really shown that much of a direct interest in humans, having been concerned with the angels, and I didn't really buy this change of tact.
As far as I could tell it hadn't been foreshadowed or suggested earlier in the season and felt almost like a contrivance to put him in a vulnerable position... to help the Winchesters.
While this is going on, Dean turns to Crowley to free him from The Bunker and set him back on the path to killing Metatron, although he is becoming increasingly concerned about the addictive nature of The First Blade and the side effects of bearing the Mark of Cain.
For the longest time Sam is out of the picture as the story focuses on the goings-on in Heaven and Dean's problems, but after Dean has a major throw-down with Metatron - which doesn't go the way we might have expected - Sam comes charging in like the cavalry, to give his brother a shoulder to lean on.
It wouldn't be a Supernatural season finale without one of the Winchesters biting the bullet, but like Kenny from South Park (and pretty much every death in comic books) you know it isn't going to stick. However, as always, the creative team behind the show have found a new spin to put on this situation, guaranteeing a fresh set of obstacles for our favourite brothers in Season Ten.
The situation in Heaven is resolved satisfactorily, and - once again - unexpectedly, tying up the major plot line of the season, but leaving some delightfully tasty threads dangling for the next season.
Next Season (spoilers if you haven't watched the season nine finale):