Hannibal watched the body disappear, outwardly unmoved but insanely curious. What could be beneath those dark waters? What did Erik feed? He didn't look at the other man at first, watching the ripples play themselves out against the shore.
"A last composition." Hannibal very carefully did not say opera, not wishing to evoke Christine once more. Erik was doing plenty of stirring in that particular pot all on his own.
He finally turned his full attention to the master musician, his face still, unflinching. His demand was not negotiable in his mind, he would not waver in it. He would not be told he was being foolish. Or he could be, but he would not stand for it.
"I have been loyal to you, I have played your music better than anybody but yourself could ever play it. I have given you all of myself as you demanded it, even going against my own initial statements of being unable to avoid office hours to attend rehearsals." Hannibal remained unblinking, his unnatural red gaze fixed on Erik's ice blue. "There is no being within this City that loves your skill more than I. I would dare say I love it more than you do. For that, for all we have seen and done together, for our bond, for my affection for you, you owe me one last composition."
Even if, at the end of it, Erik did go through with the idea of ending himself, or letting himself fade away - whichever it might come to - at least Hannibal would have this. He needed this.
"Create a sonata the likes of which the world has never heard, fill it with your grief, your anguish, your loss. Or sing her praises in every note until the page bursts from your love. You could do both, bookend your beloved with your darkness. Whatever you choose, my friend. I will not dictate what you must write, only that you must."
This was the first stage of his now fully-formed plot. Hannibal would not rest until he had seen every part of it come to fruition. All of his soul would go into the execution, his will, his prowess, everything he had, into this one last - but enormous - attempt to cease Erik's foolish pursuit of solitude and death.