"At the Foot of the Colossus" is the first mission you receive from Lord Zash on Dromund Kaas. You get it right after completing "Onwards to Dromund Kaas".
Open your mission log:
At the Foot of the Colossus
Darth Skotia stands between you and the lost power of Tulak Hord. Lord Zash has a plan to defeat Darth Skotia, but it requires some preparation. Your first task is to retrieve a Trandoshan relic that Darth Skotia hid beneath the unfinished colossus. To find the relic though, you'll need the archaeological plans of the site. Travel to the unfinished colossus and gather the fragmented archaeological plans from the rebel slave engineers.
Your task is to collect three fragmented archaeological plans. Travel to the Kaas City Central Taxi and from there take another taxi to the Spaceport Speeder and travel Southwest to Outpost Tempest, or take the speeder to Kaas City Entrance and travel SE to the same outpost. From the outpost, exit to the west and then turn south to arrive at the Unfinished Colossus. There, go south on the road through the slave camp, turning east onto the construction site.
Kill enough Rebel Slave Engineers until you get three of those fragmented plans. Then, use your holocommunicator to contact Lord Zash so that she can piece together those fragments. Click on the holocom button. Lord Zash asks you if you have found the archaeological plans. Your response choices are:
They got a little dirty
Of course
Do I make mistakes?
Choose the third option. Lord Zash sees in the plans that there is a chamber hidden under the Colossus itself. She'd bet her complete collection of Naga Sadow's Yavin Four writings that you'll find what we're looking for in this chamber.
Your dialog choices are:
How do I get in?
Yest, master.
I'll break my way in!
Choose the first one to ask Zash how you can access that chamber. She says that there should be a hidden entrance near the colossus. It looks like Skotia has an entire underground base. You're looking for a tablet. The tablet is the symbol of leadership of an obscure Trandoshan cult - the lizards believe it was a gift from their deity, the Scorekeeper. Skotia stole the tablet and uses it to exert control over his Trandoshan bodyguards. Give them their relic, and Skotia's power over his bodyguards will turn to vapor.
The dialog wheel now shows the following options:
And then they'll kill him
I get it
I don't understand
Choose the first option. His own defenses will be his downfall. But Zash says that you could try it - might weaken him a little. Skotia's not stupid enough to retain guards who could actually overpower him. The main thing is to keep Skotia's bodyguards off you. The plans suggest Skotia's apprentices guard this base. Lord Zash does not doubt they hold the keys to acquiring the Trandoshan tablet. Best kill them all to be sure.
Your task, now that you've found the archaeological plans, is to go to Darth Skotia's bunker. You can enter through the Colossus Construction Access Tunnel to the south. Enter the tunnels, and fight your way through the slaves, then take the exit to the south and into the story area. Skotia's security is activated. Your task is now to disable the security station, as well as monitoring stations one, two and three. Locate them on the map and disable each one of them. Darth Skotia has amassed an army sized force of followers in his hidden bunker beneath the colossus. Dispatch these forces in the hidden bunker and stop the underground operation. Defeat 25 of Skotia's Bunker Forces to complete bonus mission: "Bunker Busting".
Once you have disabled the security consoles, you can now unlock the door to Darth Skotia's hidden reliquary. Open the Reliquary door and enter. You will have to fight some Bunker Guardian Droids who are guarding the door. Then, you need to find the Trandoshan Relic. There will be a boss inside the room, Lord Ogathu, a level 11 Warder Elite Boss. Kill him, and take the Relic from the table.
Your task now is to return to Lord Zash in the Sith Sanctum in the Citadel to report your success. You should quick travel to the city and head to her chamber.
You inform Lord Zash that you have recovered the Trandoshan relic. Zash says that the Trandoshan bodyguards are only part of Skotia's defense. His greatest weakness is that he's mostly machine. The rogue Sith Lord Grathan is holding a cyborg expert named Dorotsech captive. He has developed a neutralizer for Zash, the kind that should destroy Skotia's cyborg elements. Find Dorotesch, get him to tell you where the neutralizer is and then silence him. Grathan's estate is in the jungle - interrogate the scientist. With any luck, Skotia will soon be out of our way. And then we'll be free to pursue Tulak Hord's lost power as we please.
This concludes the mission "At the Foot of the Colossus" and starts "Dismantling the Machine".