Wonder about this? Wonder if the bearing that Ben gave to Michael and Walt to leave on (325 - which is different than the freighter bearing) actually sent Michael and Walt back in time to where Ben could recapture Walt and make Michael work for him - getting him in on the freighter and all - also actually making it so that Michael was NOT on flight 815 and therefore not on the 815 manifest that the freighter crew memorized. That way the crew wouldn't know that Michael knew, and was working for, Ben. And Ben, essentially, still has Walt captured and is still using him. That's why he could appear to Locke in the bone pit. He is still somewhere on the island.

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