The Tunarian Plot  

This quest begins when you examine the parchment found on Laena's ghost.

After this you must kill some Tunarian Protectors to find the missing pieces. Once you have them, examine them.

Next up you must kill a Tunarian Bearmaster for the remaining piece. Examine it once you obtain it.

You must then return this parchment to Charles Arker. He'll take it and ask you to meet him at the Nook at +126, +1.77, +32.

If you go there and meet him he will ask you to take the parchment to the fire at the Outpost and burn it. This can be found at the bank at -8.46, -3.97, +117.20.

After doing this a Field Investigator will spawn, talking to her opens up the 'Checking on Charles' quest.