Hi,
this will probably be the last group of hostages you 'll free. They are located on the east side of the map inside the ghost ship. This achievement belongs to the main campaign and is not missable.
The ghost ship features a big predator challenge room. But the good thing is that this challenge is rather easy.
Start with taking out the sniper.
Then, attract at least for goons by hacking the kraken. When they are standing right under it, hack it again to release the poisonous gas.
Go on by attracting yet another group of goons to the big skull. When they are near hack the skull again and perform takedowns by pressing
.
This should leave you with just a handfull of goons left.
You can still hack the fusebox up high in the middle of the room to turn off the light and take them out while they are blinded
( which could help you with the 15 kills if you're still striving for them) , or you simply deal with them the old fashioned way
When you're done, safe the officers and the achievement unlocks.
If you need additional help, jump to minute 33 in the video below
(video credit: Batman Arkham Videos)
Hope this helps you guys :-)
Any improvements? Please let me know in the comments below!