The Docks challenge will require the use of Morse Code. Head to the Warden’s Office in Sully Port, where you will find a Morse Code machine. You must listen to the code coming from the lighthouse and input it into the machine.
It is worth noting that Long blinks are represented as dashes, while the short blinks are represented as dots.
To input the response into the machine, a dot can be inputted by holding the button for half a second. A Dash is created by holding down for more than three seconds. The code that you will need to input is anywhere from 4 to 17 characters long.
If you happen to make a mistake, the Warden will laugh, whereas your character will speak if you were successful. This challenge is all about trial and error, with many often just guessing the pattern.
With the code complete, head towards the Infirmary and get a single Zombie kill. As a result, it will spawn a ghost Zombie, in which you will need to Spirit Blast him in order to stop him from moving. Have everyone interact with the Zombie and then kill other Zombies in close range in order to charge it. This will cause the Zombie to follow a member of your team. With the Zombie following, take him down the Gondola and to the Dock Portal.
Don’t forget to collect the red stone again, which the Zombie dropped exactly where it standing.