This quest is a follow-up to the quest "Claiming What's Due." It begins below the deck of the ship on which Edward and other pirates are being transported to Seville. Edward and his fellow sufferer manage to break free from their shackles.
Shackled in bilboes in the hold of a Spanish treasure ship, Edward decides life would be better if he escaped.
To retrieve your gear, you must make your way to the other end of the ship's cargo hold. Your friend will take down the first soldier. In the next room, you'll see two more soldiers with their backs to you - take care of one of them, and your friend will kill the other.
Next, head over to the last soldier and take him down - after that, you'll be able to collect your equipment.
After gathering your equipment, you'll spawn on the deck of the ship. You need to free four groups of prisoners across four ships. Try to stealthily eliminate as many enemies as possible, entering open combat only if that fails.
Start by stealthily eliminating the first soldier standing with his back to you. Next, hide behind the railing and whistle to lure over the brute with the axe.
Then, hiding behind the crates and whistling, take out the remaining five soldiers.
Once the area is clear, approach the prisoners and free them.
Once you free the prisoners on the first ship, step onto the beam to the left of the ship's bow and jump to swing across to the next ship.
You can kill the first two enemies on this ship by performing a Double Assassination.
Hide behind the large crate slightly further back and whistle. This way, you'll lure over the next three soldiers one by one - including the brute with the axe - allowing you to assassinate them.
Free the prisoners on the second ship and walk along the ship's bow to reach the stern of the third ship.
When you jump onto the deck of the third ship, stick to the left side. After a moment, one of the soldiers - the one standing by the mast - will walk over to the one by the crates. Take advantage of this to quickly approach them and perform a double assassination. Next, kill the third soldier standing near the wheel.
You can also finish off the two soldiers guarding the prisoners by performing a Double Assassination. Just be careful not to knock over the bottles standing nearby as their clinking will alert them.
Free the prisoners on the third ship and then jump into the water and climb aboard the fourth ship. Climb up near the stern of the ship (the rear section), and you won't have to fight anyone.
Use the hatch you find there to get below deck.
Below deck, you'll encounter four soldiers. You can eliminate the first two using a Double Assassination, while the other two are standing alone with their backs turned to you. At the end, there's the final group of prisoners you need to free.
Once you free them, you'll automatically return to the deck of the ship.
The captain is on the deck of the neighboring ship. You can jump over to it or swim across and defeat him in combat, but there's a more interesting way. First, use the lift to get up to the mast of the ship you're on.
Then, by jumping between masts and walking along the rigging, make your way to the neighboring ship and perform an Air Assassination at the end.
Your main goal is to reach the position marked by the marker and prevent the ship from being destroyed. Damage can be caused by both enemy fire and the raging storm. To minimize damage from enemy fire, hold Brace when enemy cannonballs are incoming. When you see a giant wave ahead of you, point the bow of the ship directly into it instead of sailing past it to avoid damage.
Also watch out for incoming lightning strikes - signaled by blue circles on the water - and waterspouts, which cause really nasty damage.
Once you reach the destination, this quest will end and the next main quest will begin - This Tyro Captain.