Good idea Inferno, I agree. I'll use your suggestion, and just add some details to flesh it out.
Go talk to d'Artagnan and convince him that it's in everyone's best interests to ensure Jim and Ron don't survive, since they would surely come looking for him if they were rescued and they'd bring another crew to help them. After all, Ron had always told you how suspicious he was of d'Artagnan's motives and ambition, so he certainly knows it was him responsible. Tell him you admire his ambition, but would hate to see him take the position of captain one day just to lose it when Ron sneaks aboard the ship to kill him when he least expects it. Everyone knows Ron is stealthy enough to manage it.
Once he's convinced that making sure Jim and Ron die is the best course of action to ensure the safety of his ambitions, assuming he even required any convincing, then suggest he does what
most pirates do when they maroon someone: Leave the prisoners on a sandbar at low tide, not an actual habitable island. This will make it nearly impossible for them to be rescued.
Then tell him that to be extra sure, you'll contaminate their flasks of water, and ask him if he meant it when he said there's no poison on this ship. If he confides in you the location of some toxic substance, go get it and mix a sufficient dose into two flasks of water. If he says there is no poison, simply fill the flasks with saltwater instead. Mark both flasks with a visible marking, like an X, either etched or drawn on it depending on the material (this is to identify the flasks, so you don't end up drinking from one). Afterwards, bring d'Artagnan the flasks of water and tell him to make sure those are the ones the prisoners are given.
After this, get your gold doubloons, a dagger that can't be traced to you, an unloaded pistol that can't be traced to you, and three or four loaded pistols with a handful of bullets from your personal storage, or the ship's storage if need be. If this is necessary, then use stealth to avoid detection while going to collect these items. If anyone sees you enter, simply say you were checking the storage as part of your boatswain duties, while keeping the stolen goods effectively hidden.
Wait until the middle of the night, then take these items to the brig and execute Jim and Ron yourself, right through the bars. Keep your guns hidden in your waist band, strapped to your legs, in your sleeve, or wherever else they'll be out of view. Try to keep them accessible. Put the dagger in your pocket.
Use your stealth to avoid detection. If any guards are positioned in a way that you can't get by them, go talk to them and use some gold doubloons along with your charisma to convince them it's better if these fiends are never given the chance to be rescued. They never gave Peavey a chance, just murdering him in his sleep like pathetic cowards, so we shouldn't give them a chance either. Assure them you'll avenge poor Peavey, and all they have to do is look the other way, with a nice profit on the side.
If the guard will not move out of the way for some reason, ask them "Are you sure? I have quite a lot more coins to spare," and while nonchalantly rifling through your pocket as if you're getting more coins, swiftly pull out the dagger and stab them in the throat repeatedly until they collapse motionless. If there is another guard present, instead of dropping the stabbed guard to the floor, keep him propped up and use him as a shield. Draw your pistol, and while using the first guard's body as protection, shoot the other guard.
If there are any actual physical barriers preventing you from reaching the brig, use these same methods to either have the guards let you through, or force your way through. If no guards are present, but a barrier exists, find someone who would know how to open it and have them do it. If the person who can unlock it is asleep for the night, find them and either stealthily steal the key, convince them to open it, or kill them and take the key (in that order).
Use any means necessary to access the brig, even if it requires setting something on fire to destroy a barrier or lure guards away from their posts. In a worst case scenario, come up with a creative way to bypass any hindrances and do that.
Once any guards have been successfully bypassed, go into the brig and talk to Jim and Ron through the bars. Charismatically tell them you voted for their innocence, but since it didn't work, you're there to free them instead; the plan is to hide them somewhere, like your quarters, and convince the crew they jumped overboard. Close your offhand as if you're holding something and place it through the bars, then tell Ron something like "Here, this should work as a lockpick," using your charisma to convincingly bait him over. When he reaches out his hand so you can drop the supposed lockpick in, grab his wrist and yank his arm through the bars, pulling him up against them. Use your other hand to take out your dagger, and stab him in the throat repeatedly until he goes limp.
Next, use your charisma to calm Jim down, telling him that you know he wasn't the accomplice, but that Ron was the real killer, so you couldn't let him go free. Tell him it's time for him to escape so he can follow the original plan, to successfully hide on the ship while convincing the crew he must have gone overboard already. Toss the bloody dagger on the floor, and offer Jim the unloaded pistol you brought with you, holding it out by the barrel, and tell him you want him to take your weapon so he knows he can trust you. If he resists, tell him you'd have simply shot him with the gun if you wanted him dead, instead of giving it to him, and remind him of your long friendship to convince him to come forward and take it.
As he walks forward to take it, accidentally release it a bit early so it clatters to the cell floor right by the bars, and use your charisma to make it look convincingly like an accident. When he bends down to pick it up, pull out a loaded pistol and kneel down while aiming it at his lowered head. In the most hateful tone possible, whisper through the bars, just loud enough for him to hear, "I killed Peavey and set you up." When he looks up at you in shock, have a wicked smile across your face, so the last thing he sees is that expression of yours while you're aiming your gun at him. At that perfect moment, shoot him through the head, splattering his brains across the floor of the cell.
Make sure both prisoners are dead, using multiple shots if necessary to be able to verify the deaths. Do not unlock or open the cell at any time, unless it would be somehow necessary to kill the prisoners, in which case it should be done, but only while taking the utmost precautions and using charisma to get them into a sufficiently vulnerable position before executing them.
If any guards were killed in the process of getting to the brig, be sure to leave the unloaded pistol in Jim's hand, where it should have ended up anyways. Toss the dagger just inside the cell as well. This should be enough evidence to convince people Jim somehow managed to lure a guard over, got a hold of his weapons, used the dagger to kill Ron, then killed the guards, and simultaneously died from being shot in the process. If people don't draw that conclusion themselves, you can always charismatically suggest it.
After Jim and Ron have been executed, pause and reflect on the day's success with a long "Yarrrrr...."
Go back to your quarters and change your clothes, wiping any remaining blood off yourself before putting on new clothing. Throw any weapons, clothes, or other items with blood on them into the sea immediately. Afterwards, go to bed, smiling with a great sense of satisfaction, and have a fantastic night's sleep.
Post has been edited 3 time(s), last time on Mar 9 2013, 3:27 am by Azrael. Reason: Typo.