I think Penelope has left Charles after discovering what he has been doing in regards to the island and Desmond. She has probably dropped out of sight along with Desmond and is hiding from Charles. This is why Charles says Ben will never find her. Charles can find and move her at a minute notice. Also, if Penelope was on the island with Desmond, I believe Charles would of been asking how to get back to the island instead of saying he will never find her. And Ben would of known if Penelope was on the island just like he knows everything else.

As far as th island is concerned, I do not think Ben can get back to the island. Something happens which forces him to make a fast, hasty exit from the island. Whatever or whoever was coming after him on the island forced him to make a one way gate out of there as opposed to a open portal to and from the island. So Ben has to either wait until someone opens another gate/portal or when the island "shows" itself like it did at the artic station.

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