If you're playing "Tales of a Sea Hawk" and you take the "Silver Train" sidequest at the right time in the story, it is possible to end up with Will Turner as a permanent companion.
The problem is that he's unremovable and immortal, so he really is a permanent companion - you can't sell his ship and you can't even let him be sunk to clear his companion slot.
Option 1: add some code to "Tales of a Sea Hawk" to check if Will Turner is a companion when he shouldn't be, then remove him. Apart from denying the player a bit of deviousness, the snag is that the same thing might happen in other storylines.
Option 2: make Will Turner removable and mortal at the end of "Silver Train". This won't affect the sidequest because this is where he's supposed to split the loot with you and then disappear. If you manage to get him back, he's no longer protected. For additional amusement, make Elizabeth Swann an officer on Will Turner's ship so that if you do manage to get Will back, you get Elizabeth as well.
I'll leave it to you to figure out how to get Will Turner back.
The problem is that he's unremovable and immortal, so he really is a permanent companion - you can't sell his ship and you can't even let him be sunk to clear his companion slot.
Option 1: add some code to "Tales of a Sea Hawk" to check if Will Turner is a companion when he shouldn't be, then remove him. Apart from denying the player a bit of deviousness, the snag is that the same thing might happen in other storylines.
Option 2: make Will Turner removable and mortal at the end of "Silver Train". This won't affect the sidequest because this is where he's supposed to split the loot with you and then disappear. If you manage to get him back, he's no longer protected. For additional amusement, make Elizabeth Swann an officer on Will Turner's ship so that if you do manage to get Will back, you get Elizabeth as well.
I'll leave it to you to figure out how to get Will Turner back.