In the OCU Front Base, upgrade your wanzers if necessary and head to the Military Office. Olson says that the regular army has already left and you must go after them to Fort Monus.

Before you leave the base, Olson comes after you and change your orders to find someone a deserter from the USN at the military facility in Fort Monus. When you reach the area, Hans detects units desperately pursuing the deserter. When Hans contacts the unit and it responds, Yang recognizes the voice and rush after that unit. Your unit is detected and Driscoll orders to destroy all of you.

3 Missilers in CICADA II Lv 14 HP 450 (Body 144 Arms 192 Legs 114) FI 77 ST 0 LG 22 AG 182

4 Attackers in GROP SP-V Lv 15 HP 390 (Body 120 Arms 168 Legs 102) FI 41 ST 36 LG 0 AG 156

3 Attackers in ORCS II Lv 15 HP 294 (Body 96 Arms 120 Legs 78) FI 35 ST 25 LG 0 AG 117

2 Carriers in Natural Lv 14 HP 200 (Body 200) FI 0 ST 24 LG 0 AG 205

Commander in S-ORCS Lv 14 HP 408 (Body 132 Arms 180 Legs 96) FI 0 ST 80 LG 51 AG 169

Military Commission 20000

Destroyed Enemy Bonus 7944

Yang starts as a guest character in this mission. After 3 turns the unidentified is revealed to be Yang's little brother, Yeehin (And for some reason Yang refers to herself as Mei Fa*). After that, you can once again control Yang, so head to destroy the wanzers. Notice that a few wanzers start out near to your right, so destroy them first then head all the way down destroying the enemy units.

After the battle, Yeehin is formely introduced to the party and Hans remembers the Nirvana Engine name he found while looking for info on Karen. Karen was a Nirvana Engine trasportation candidate. Yeehin never met Karen, though. He says his colleagues were all dissapearing one after another, so he decided to desert. Yeehin is still your prisoner, though. Now go back to the front base for your next mission

*Note: Yang is actually her family name, that's why she refers to himself as "Mei Fa" when calling her brother (Check the characters section). I bet this is just one pronunciations errors that occur when translating foreign names. I've seen information all over refering to Yang as Yang "Meihua"... the "Mei fa" sounds similar when saying it in Japanese, but it's basically the same thing.