Only 0.1% of players have this achievement, so here is a guide to get it! It requires the Exile DLC. To get it you need to escape with at least 20 comfort.
The Sweet Bones Achievement Guide
Phase 1: Increase edge lore to maximum
Explore each city, doing capers and operations to collect items, followers and cash. Relinquish years for cash as needed. Keep the reconnoitre verb running constantly throughout this guide, and do not go to any edge of the world locations.
If you find a shrine to the Colonel or the Lionsmith use it to upgrade your edge lore. Don’t collect any tranquility during this phase or you won’t be able to do this.
When a reckoner appears attack it immediately by employing your edge lore or a weapon. If it receives 2 wounds then it will leave a reckoner corpse, which you can relinquish to upgrade your edge lore.
Once the reckoner starts upgrading to an underboss then leave the city when practical.
When your edge lore is at maximum you can proceed to phase 2.
Phase 2: Collect obscurity
Your first action in each city should be to send messages to find the next city, unless there is a local contact to meet first. If you get the cross country card then use it to leave immediately.
The best way to collect obscurity is to relinquish traces with 2 assists deception cards. Each time you do this you will gain 1 obscurity. Example cards are any connection, discreet office, warehouse and night.
For cash the illegal fights operation is the best choice because it doesn’t require any assets, but only start it if there are no traces or reckoners on the board. Use your edge lore in the illegal fights, don’t use any assets.
Relinquish years for cash as needed if you don’t have enough to leave a city or buy a nice asset.
Attempt any capers that you find, but be careful about using any assets to complete them. If you need to leave the city fast then any assets committed to the caper will be lost.
As soon as the eye appears showing a reckoner will arrive soon, and you have at least 1 trace, then it’s time to start leaving the city. While you’re leaving relinquish a year for cash if you are below 2 cash.
If the eye turns into the face of a reckoner then consider relinquishing any remaining assets, as probably in about 40 seconds you will lose an obscurity.
Once you have at least 12 obscurity and medical credentials proceed to phase 3.
Phase 3: Find a City to Settle Down
Continue playing like in phase 2 until you draw a secluded villa card and you don’t have a reckoner in the city yet. Not all cities have villas available so it’s important to be in a city that does.
Purchase the villa by directly exchanging cash and assets, but avoid exchanging assets that improve comfort.
Use the medical credentials and the villa to repeatedly run the sanatorium operation. You’ll need 12 heart lore to complete it, the easiest way to get this is with tranquility or more properties. Each time you finish it you’ll get 4 cash and 1 obscurity.
Once you have at least 1 trace repeatedly relinquish years for cash. You need to get cash as quickly as possible.
Purchase any villas, townhouses or offices that you find in reconnoitre. Once you are down to 7 obscurity then use the send verb with temptation escape to finish. With a little luck you should have enough properties to finish with more than 20 comfort.