I believe that the Fountain of Youth is what lies in the shadow of the statue. This would explain the slow or almost non-existent aging of some characters, and also the healing properties of the island.
I also believe that Eloise Hawking is the person who hired Brahm and Illena...It seems as though she has just as much interest in the island as Ben or Charles, only maybe not enough manpower to get there. We know she was at one point on the island. I was expecting her to be Charles' sister, or perhaps even lover...But I think she is the 3rd person who now wants control of the island, and with Faraday and crew there now, Ben and Charles will have no clue...You could also tell that Ben didn't care for her...
I also believe that Eloise Hawking is the person who hired Brahm and Illena...It seems as though she has just as much interest in the island as Ben or Charles, only maybe not enough manpower to get there. We know she was at one point on the island. I was expecting her to be Charles' sister, or perhaps even lover...But I think she is the 3rd person who now wants control of the island, and with Faraday and crew there now, Ben and Charles will have no clue...You could also tell that Ben didn't care for her...