Taking the fight to a massive Gauna hive was always going to be a "do or die" mission for Sidonia's Gardes, but as the situations worsens it seems as if only the "die" part of that statement has any chance of coming true.
Desperate times call for desperate measures, and with Benisuzume scything through the platoon and an anti-planet missile well on its way, the decision is made to blow a whole in this Gauna hive using Sidonia's Super Hyggs cannon. The only question is whether anybody will still be alive at that point to take advantage of the route this should open to the hive's "master" Gauna, and with this in mind Nagate offers himself up to take on Benisuzume to give what remains of his platoon an opportunity to defeat the Gauna and escape the onrushing anti-planet missile.
Even for a pilot at skilled as Tanikaze, taking on this monstrous enemy with so much "borrowed" knowledge from Hoshijiro, and it all seems about to go awry as he's knocked unconscious in the eschewing battle. Enter a terrified Izana to come to the rescue before he meets his certain demise, only for Izana's craft to be knocked out into space in the resulting chaos. With ammo out, the game looks to be up for Nagate... except he has one last trick up his sleeve, provided to him in the hope that he might exact vengeance in the place of one of the Honoka clones. Thus, victory belongs to Sidonia as the Gauna is destroyed in the wake of Tanikaze's personal victory, ensuring the safety of those on-board once again and giving Tanikaze an opportunity to try and make peace with Kunato in particular. Even more dangerous threats remain however, which is one way of saying that a second season is on the way later in the year.
If last week's episode of Knights of Sidonia was all about white-knuckled tension, the series finale was far more about balls-to-the-wall action - something which wasn't quite as gripping as what came before but fare that was deftly accomplished all the same with just enough moments of peril and drama to work into the ultimate triumph which bookends the series. These final instalments are also a study in just how far this series has come from some faltering beginnings - its initial episodes were clumsy at setting up its major characters (although admittedly they did a great job of world-building instead), but somehow events have organically ensured that putting these characters in danger elicits exactly the right emotions from the viewer, and coupled with what feels like some major improvements to its animation quality and a narrative that grew stronger by the week, we've been left with a terrific series which I'm more than happy to know there'll be more of.