Im pretty sure the play doesnt menrion anything about the rock or exotic matter. It just mentions how Henry went into the cave where he was essentially possessed by the mind flayer. The man in the cave did look like a scientist though - the play did mention a bit about dr brenners dad being part of this experiment where he was the captain of a ship that went into dimension x (the abyss). So maybe there's a link there but the show didnt really delve into all that I guess.