Disclaimer: I own nothing, even though I want to
Faramir does not cry for Denethor. He is surprised to learn that his father cried for him at the end, and yet he can't bring himself to return the favor. He supposes that he's cried enough over the years, and perhaps that is the reason why he can't do it now, but he only feels a pang of regret for wasting useless tears on his living father instead of saving them for his dead one.
They tell him his father burned. They tell him gently, as if the words are a flame and he is a sliver of wood. As if he will crack and splinter and blacken at the heat of their touch. But he has burned before. Been soaked in oil and set aflame for the whole city to see by. He remembers the flames against his skin, eating hungrily away at his flesh until he can no longer crawl into it and hide; at his muscles until he no longer has the strength to move; at his bones because he no longer has the will to fight.
They tell him he is the Steward now. He must be the one to stand tall and hold the sky upon his shoulders, crown the sun upon his head so that they might be warm even as the rays dig into his skull like thorns. He tries to remember that this is only temporary.
But while he waits he burns, hollowed out like a candle, slowly folded over himself until he is a mess at his own feet, spilling over burnished metal because he didn't stand tall enough to burn a little longer.
Perhaps if he had been stronger, he would have tears left to spill. And perhaps, when his father was burning, he could of quenched the flames with the water he had saved so that Denethor would be more than fragments of memories in his mind. He would be whole, and clean, the Denethor that was loving Father as well as dutiful Steward. But he hadn't, and instead of water he has salt on an open wound. It burns, but he's used to that.
In his dreams, he finds his father burning, and Faramir joins him, drinking in the warmth that he hasn't felt in so long. He had always been cold and distant, like a tomb. Silent, but strong. Denethor freezes, and Faramir burns. Burns until he has nothing left to feed the flames, and they die because Faramir could not support them anymore. Still he thinks he is weak for failing to keep alive the very thing that was slowly destroying him.
Without the fire he is nothing but a charred skeleton. There is no more light, only smoke and ashes. The words are a gentle breeze upon his skin and they carry him away. He smiles through black teeth and empty eyes and looks to the West, and he wonders why the King would come now, when there is nothing left to save.