Astarion died in the water at the base of the hill during the Harpy battle. Since he is under water, I am not able to target him to revivify. I also can not talk to him to remove him from the group... I guess I'm starting the game over or going back to a really old autosave.
There is a character that can revive your party members back to camp. For the sake of not spoiling anything, i will only say that he/she can be found early in the game.
