"Lost Kingdom" is the 18th campaign mission in Ace Combat 7: Skies Unknown. The player must capture Shilage Castle and destroy all splinter Erusean forces in the area.


Jaeger: It's time for the briefing. Although, we don't have any contact from HQ, it's not like this is an official mission. Anyway it looks like the seizure of Tyler Island and the relief from Osea have been postponed. In the meantime, we just have to do what we can to survive. Since losing its capital city of Farbanti, Erusean forces have separated into smaller autonomous factions. It looks like Erusea's largest force and leading faction will pass through the area around this base. The space elevator is significant to them, so they're probably heading there.

Lanza: Should we intercept?

Fencer: Why? I doubt they're going to start a fight now.

Skald: Our top priority should be to get home. Let's go already.

Jaeger: Yeah. It's not like we have the supplies, power, or even a real reason to put up a fight. But what're we going to do if they bring the fight to us? We need to be ready to push them back. If we head inland from here towards Erusea, there's an old castle that's been converted into a stockpiling base: Shilage Castle. It's currently occupied by some of the Erusean forces that broke off, but we need ammo and fuel. They appear to have converted a freeway into a runway, so we can expect them to have the capacity for air combat. But they'll be easier to handle than Erusea's lead faction. Well, we can't use all our aircraft to attack. The transport carrying the stolen supplies needs support. Okay, Strider Squadron, you head out first and neuter the dogs at the stockpiling base. Rendezvous with Cyclops Squadron, who will bring the transport. Then we bring the supplies back to this base.

Fencer: Got it.

Húxiān: Aircraft are our only threat.

Lanza: Sounds good.

Jaeger: We'll make it. We're all gonna fly home. Together.



There are no allies within the area, so all UNKNOWN targets will automatically be identified as hostile. The player must destroy all of the anti-air defenses in order to secure a path for the transport. Upon destroying the targets near the castle, Sol Squadron, without Mister X, will take off from a tunnel and begin to engage the player. After destroying two of the planes, a loud blast will come from far off, alerting the player to an attack via a railgun. The first and second shots, however, can never hit the player.

Mission Update[]

Mister X will enter the combat zone, using an X-02S Strike Wyvern equipped with an EML. The player must shoot him down, though it will take multiple missiles and Mister X is invincible before "There are pilots like you on every generation, and I felled every last one of them". The remaining half of Sol Squadron will retreat and cannot be shot down, so they should be ignored.

Occasionally, Mister X will enter a scripted sequence where he flies away from the player, charging his railgun, and once done will turn on a dime to face the player, letting loose anywhere between one to four railgun shots. Rarely, he will charge his railgun, then perform a Post Stall Maneuver to attempt to hit the player with an EML shot while doing a kulbit. Getting hit by a railgun shot is scripted to put the player at 99% damage. However, getting hit by another railgun shot while still at 99% will still kill the player.

After Mister X receives enough damage, he will cease use of the railgun, and will revert to using missiles against the player. The mission is completed upon the downing of Mister X.

Enemy Lists[]

Standard Units[]

Section Unit Points Count Notes
Initial Icon-GroundEnemy WATCH TOWER 100 2
Icon-GroundTGT SPC 200 3
Icon-GroundEnemy APC 120 4
Icon-GroundEnemy TANK 150 3
Icon-GroundEnemy HOWITZER 120 2
Icon-GroundTGT TRUCK 120 4
Icon-GroundEnemy TENT 100 5
Icon-GroundTGT AA GUN 150 8
Icon-GroundTGT XSAM 200 4
Icon-GroundTGT AD TANK 500 4
Icon-AirTGT AH-64D 200 4
Icon-AirTGT AV-8B 320 2
Icon-AirTGT F-16C 400 2
Icon-AirTGT GRIPEN E 500 3
Icon-AirTGT Su-30M2 "SOL" 800 4 [note 1]
Mission Update 1 Icon-AirTGT X-02S "MISTER X" 2000 1

Special Unit[]

Unit Points Notes
Icon-AirEnemy YF-23 "LYNX" 1,900 [note 2]


The resupply went well. We should be okay on food and fuel reserves for a little white, at least. Luckily the rumor that the Erusean Army is advancing nearby is only a rumor. There's no sign of them from the skies. Rumors, rumors, rumors. This is what happens when you lose communications. But we got one good fact. The plane Trigger shot down was an advanced model of the X-02 Wyvern. It was developed in the last Continental War. Erusea had a lot up their sleeves. Apparently, they were even supposed to have Belkan aircraft back in the first war.[sic] What if Trigger couldn't shoot it down? Just thinking about it gives me chills. We're lucky to be here. In war, you never know who's lurking behind the curtains. But it looks like everything's loose now. A solid chain of command, rest periods after sorties, a battlefield where you know friend from foe... All of that's gone now. Lost in a fog of confusion. It feels like a distant dream. Now, just how the hell are we going to get out of this mess?

S Rank[]

Earning an S Rank on this mission requires earning a combined score and time bonus of 37,050 points or more.

The maximum time bonus available is 25,550 for completing the mission in a total of 12 minutes and 30 seconds or less. This includes time spent retrying from the checkpoint. If the player can complete the mission in that amount of time, they only need 11,500 points from destroying targets in the mission itself to earn the S Rank.

If the player goes past the 12 minute and 30 seconds threshold, the time bonus decreases by 50 points every second, so the player must compensate by destroying more targets to hit the 37,050 point threshold.


  1. Once two Su-30M2s are shot down, the remaining two will become invincible and fade from the radar after the mission update.
  2. The player must have completed this mission at least once, and must be playing on Normal difficulty or higher. Destroy all the enemies along the route and reach Shilage Castle in about three minutes. LYNX spawns slightly north of the castle about the time that the F-16 takes off.