- "Take your final shot. End this Antares."
- ― Burford
This variant of the mission is only available in multiplayer. However, it can be repeated in Free Mission in single-player afterward. The 12A variant is also available during both single-player and multiplayer.
Burford: The Valahia have launched their attack on London. Allied forces are already engaged with them. They've deployed the same Spiridus we saw over Tokyo airspace, meaning London is in serious danger. So far they haven't revealed any new weaponry other than what we saw in Tokyo, but stay sharp. Analysis of data suggests the Spiridus lacks mobility due to its massive size. Use a high speed aircraft for hit-and-run tactics. Or a high spec one for close range attacks. It won't get away from us this time! Antares Squadron, destroy the aerial base Spiridus. This battle will settle everything. You are ordered to come back alive and victorious!
The Spiridus will be flying over London and preparing to attack. The player must destroy its three anti-ground electrolaser cannons - one on each end of the Spiridus, and one in the back. They will only be vulnerable when charging up for an attack. Unlike the 12A variant, there is no jamming in this mission.
There will also be two Su-27s protecting the Spiridus, as well as four AA guns on the Spiridus itself. The AA guns will constantly respawn when all four are destroyed; destroying only three of them and keeping one alive will prevent the other three from respawning.
Mission Update 1
When all three electrolaser cannons are destroyed, a fourth one will appear, this time as an aerial weapon. Players must avoid the laser for the remainder of the mission by flying very fast or staying below the Spiridus.
Multiple AA guns, flak guns, and SAMs will appear on the Spiridus. Fire control units (labeled as "FCU") will appear as well, and these must be destroyed to lower the Spiridus's power. After two waves of FCUs have been destroyed, the anti-air electrolaser cannon becomes vulnerable. Destroying the laser cannon will continue the mission.
In addition, the Spiridus comes equipped with IRCMs - large plasma spheres that act as countermeasures and redirect missiles that approach them. Players will have to fire their missiles around the IRCMs, or rely on unguided weapons like machine guns to destroy the FCUs and laser cannon.
Mission Update 2
The Spiridus will begin ascending and prepare an attack with its Balaur. All players must attack the Spiridus's heat vent to destroy it and prevent the attack. The heat vent will take a lot of hits: the equivalent of 10 missiles (or 20 in multiplayer). While this time is not stated, players have 140 seconds to destroy the heat vent, otherwise the Balaur will fire and mission will end in failure.
Destruction of the heat vent will complete the mission.
Earning an S rank on Nightwatch does not require completion within a certain time or score range. Instead, the S rank requires minimal damage to London. The MPG must be at 90% or above upon completion of the initial stage.
- F-15E Mr.8 - appears during the first Mission Update after two of the Spiridus's FCUs are destroyed
Burford: Spiridus has been destroyed. Well done, Antares Squadron. London has taken a lot of damage but the worst case scenario was avoided and that's what matters. Hopefully this will put Valahia back in their place... but we're at a loss as to what they want. The Valahia's motives are still unclear. They targeted Tokyo and London, two hubs of economic and financial power, with high spec weaponry. They operate on too large a scale to be terrorists. They obviously have firm financial backing. Oh, uh... This isn't something I should be discussing right after you finished an operation. Thank you for your efforts in protecting London. You deserve a good rest, Antares Squadron.