THEORY ONE
THEORY: ward cameron killed sarah, wheezie and rafe's actual mother.
EXPLANATION: rose is, as you know, the cameron kids' step-mother, as sarah once told her, "you're not my real mother," etc.
and, as you also know, ward has a... habit of killing people with his gaff hook, as he has gaffed kevin ratter and david cruz, and killed (or "killed) john b's father. he also attempted to gaff john b on the "my druther's" when they went fishing.
but all of his killings had something in common. he killed, our attempted to kill, people he knew were after the gold and were very close to finding it.
my theory is that he killed the kids' real mother. i believe that he may have killed her because she knew too much about the gold.
