Meeting with Samuel | Mission 8 - The Loyalists Dishonored Guide
Last update: 11 May 2016
New Main Quest: Meet Samuel on the beach beyond Emily's tower
Since Samuel will approach the tower (and not the docks as he usually does) it's best to use the key you have just obtained, to open the nearby door (the above screenshot).
New Main Quest: Embark for Kingsparrow Island with Samuel
After you reach the balcony, teleport downstairs (you could just as well use the stairs to get there, but this would take more time). Wait for Samuel's boat to reach the bank and start a conversation with him. Confirm that you want to leave for the place where Emily is being kept captive (the upper-right dialogue option).