Mission 5 was an altered representation of a fragmented genetic memory.
- Edward Kenway: Come on! No time to waste!
- Pirate 1: Whatever that officer has, it could be bad news if we don't stop him.
The pirates made their way through the Navy's simple defenses, evading or eliminating any soldiers from the British army they encountered until they arrived at the mouth of a cave bearing distinct Isu architecture in the form of an angled doorway. Inside the first chamber, they saw Captain Stewart and two redcoats inspecting the black and gold pillars that jutted up from the cavern floor. The pirates walked in, surprising Stewart.
- Captain Stewart: You scum! How did you follow me?
- Pirate 2: You didn't exactly hide your tracks, ye daft fool. What is this place?
- Captain Stewart: That is no business of yours. All you need to know is that it's MINE. I've found a vault!
The redcoats attacked the pirates but were swiftly defeated, leaving Stewart along and outnumbered. Before he could elaborate on the Vault's purpose or boast about how he intended to use it, Edward ran up from deeper within the Vault and plunged his Hidden Blade into Stewarts's neck, instantly killing him.
- Edward Kenway: *SIGH* Bloody fools chasing shadows. We need to get out of here. There's nothing here for us or Garnet.
One of the pirates responded in an aggravated tone.
- Pirate 2: What? We just got here. There's no treasure?
- Edward Kenway: This vault is dangerous. The Federation's survival is a lot more likely if this vault goes untouched.
- Pirate 2: At least hand over the goods. You owe me that week's worth of rum after all!
Edward and the crew of the Sea Dog's Bite pursued Captain Stewart to a vault in the Caribbean and killed him before he could activate it. Although the pirates wanted to loot the place as compensation for their troubles, Edward felt that the vault was ultimately dangerous and decided it would be safer if it were forgotten, and so the site was abandoned.