You get the mission "The Separatists Stronghold" after completing the mission "Oradam Village"
Open your mission log:
The Separatists' Stronghold
Following the intelligence you retrieved, the rest of Havoc Squad set off to recover the stolen ZR-57 orbital strike bomb from the separatists' stronghold. Shortly after they breached the facility, however, all contact with the squad was lost. It's now up to you to ensure that the separatists cannot detonate the bomb. You need to hijack their communications system to broadcast the bomb's disarm code. Use the data spike you've been issued on the communications console inside the separatists' stronghold.
Your task is to use Data Spike on Separatists' Comm Console. The stronghold is located to the Southwest of Oradam Village. On the way, stop at the Volcano Camp to bind and unlock the taxi rout there. Then keep going south, and enter the stronghold. Locate the entrance to level 2 on the map, and fight your way to it. Climb on the ramp that takes you to level 2. Then go north to the communications console. There are large concentrations of separatist forces in the area so be careful. Neutralize them all group by group as you make your way to the comm console. The Imperial officers are particularly tough. When attacking them, make sure to first neutralize the imperial soldier standing near them before focusing on the officer. If you cannot defeat those officers, then die and call a medical probe, and while you are immune advance towards the console and take cover to the side. Kill the soldiers near the comm. You probably die again, but next time, heal to full health and just go straight to the console and interact with it. You should be able to broadcast the disarm code just in time before getting killed again. Then return to the medcenter in 2nd level.
Use your personal holocom. Lieutenant Jorgan congratulates you on a job well done. Report that you've encountered Imperial Soldier guarding the bomb. He says that he saw that through the armor-cam. Imperial soldiers operating right alongside the separatists. We need to know how deep this connection goes. Jorgan wants you to continue further into the base. Finding the rest of Havoc Squad is now priority one. If they've been captured, they might be able to tell us more about what's going on in there. If possible, you should also retrieve the ZR-57. It costs about forty million credits. So Command would like it back. But your squad-mates are the main objective now.
Your task is now to attempt to locate your squad-mates inside the separatists' stronghold and learn the extent of the Empire's involvement. Locate on the map the Entry Point to the 3rd level of the Stronghold. It should be on your East. Use the map to find the room where Havoc Squad is in. When you finally reach them, they don't appear to be being held against their will. Tavus and Havoc Squad have defected to the Sith Empire! Tavus explains that the Republic no longer values her warriors, even the very best among them. Tell him that only cowards defect. The Republic Senate doesn't actually believe it can win another war against the Empire. The Republic abandoned them, during a mission on Ando Prime. Tell him you'd never betray the Republic. Fuse thanks you for locating the ZR-57 for them. They intend to present it as a present for the Empire. Tell them that you deactivated it. But they think you are bluffing. As they board the ship to leave, Commander Tavus orders Colonel Vorr to kill you. Defeat the Imperial Soldiers. Then return to Republic Command Center in Fort Garnik to report this information at once.
Depending on your previous actions, you should also have received some new mail by now. Private Farn sends you one with the subject: "Virk is Going Down":
Great news! Lieutenant Virk was just dragged out of our barracks kicking and screaming. They said they're charging him with treason! When he came in looking for "Volunteers" to catch you out in the field, nobody went for it and he stormed off. We decided to all report him together but I never expected such a fast reaction. I guess his crooked friend couldn't cover him this time. If you hadn't stood up to him this would never have happened. Than you so much!
Make sure to take the attached credits by clicking on the icon in the lower left corner before deleting the message.
Zak had sent you a mail titled: "Feeling Better":
I want to thank you again for helping us with our illness. I hope the information we gave you was useful. Jaller won't speak to me, but she isn't spending any time with her old "friends" either, so I have hope. I wouldn't even have that if not for you.
When you enter the command center, Jorgan is talking to General Vander. Jorgan is being demoted to Sergeant because of what happened with Havoc Squad. Tell General Vander you are reporting for debrief. Vander introduces himself as the Republic chief of operations for Ord Mantell. He thanks you on behalf of the Republic and the people of Ord Mantell and congratulates you for your courageous actions in disabling the stolen ZR-57. Your heroic efforts saved countless innocent lives. In recognition of your valiant service, he promotes you to the rank of Lieutenant. As the last remaining member of Havoc, the duty of rebuilding the squad falls to you. Havoc is your command. To get the process started, he has decided to assign Sergean Jorgan as Havoc's first new member.
Your work on Ord Mantell is done. The General has a shuttle prepared. You're going to Coruscant for your next assignment. When you arrive on Coruscant, report immediately to the head of SpecForce division, General Garza. She'll be issuing your orders from now on. Your shuttle is waiting for you in the landing bay.
This unlcoks Aric Jorgan as your companion. It also concludes the misison "The Separatists' Stronghold" and the Trooper class missions on Ord Mantell. You now want to finish all other side missions in this area before heading to The Republic Capital, Coruscant, for the mission "New Assignment"