Something struck me when rewatching "the Cost of Living" after the end of season 4. It's been said before that after the attack on the barracks, it's possible that Claire entered a state of existence between life and death, until the deceased Christian Shepherd takes her hand and leads her into the jungle where she is now permanently stuck in limbo (the Cabin.)
It's also been heavily considered that Christian Shepherd is merely a guise of the Smoke Monster. And while his conversation with Locke in "Cabin Fever" and his role in the mobisode "So It Begins" lead me to think he is not just a mask the monster takes, the connection is still possible. This is supported by the events leading to Mr. Eko's death in "Cost". As where Christian approaches Claire and leads her away, Yemi approaches Eko and offers him redemption.
I believe Eko died in the hatch or in the polar bear caves that Locke found him in and Yemi appearing to him is the Smoke Monster offering him his chance to enter the "undead" realm that exists on the island. Eko refuses however, and the island lets him stay dead. Perhaps had he accepted redemption, he would have been chillin in Jacob's Cabin with Claire and Christian in "Cabin Fever."
Theory by JBoyd
It's also been heavily considered that Christian Shepherd is merely a guise of the Smoke Monster. And while his conversation with Locke in "Cabin Fever" and his role in the mobisode "So It Begins" lead me to think he is not just a mask the monster takes, the connection is still possible. This is supported by the events leading to Mr. Eko's death in "Cost". As where Christian approaches Claire and leads her away, Yemi approaches Eko and offers him redemption.
I believe Eko died in the hatch or in the polar bear caves that Locke found him in and Yemi appearing to him is the Smoke Monster offering him his chance to enter the "undead" realm that exists on the island. Eko refuses however, and the island lets him stay dead. Perhaps had he accepted redemption, he would have been chillin in Jacob's Cabin with Claire and Christian in "Cabin Fever."
Theory by JBoyd