Well, another thing to keep in mind about Locke: He said to Sayidd that the reason he hit him and destroyed the transceiver (when he took Sayidd to the plane) was that he would do anything he felt was necessary for the good of the group.

Think about that. Anything. And he (Locke) is the one who decides.

And he likes to have secrets and one-up Jack.

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charlie98210
"Whoa!" she said. "Cry 'Havoc!' And let loose the dogs of war!"
And, like Banquo's ghost, they just won't go away.