Mervyn Peake did not intend the "Gormenghast" books to end with Titus Alone -- he intended the series to continue and eventually to tell the whole of Titus' life story.
Of the subsequent books, we know the projected names of the first two: Titus Awakes and Gormenghast Revisited, and the opening fragments of the first of those books appear below. To the best of my knowledge (and I would be happy to learn otherwise!) this is all that was written of them.
The fragments are clearly no more than early drafts -- the repetition that appears in the first section makes this clear, and the whole has an rough feel to it, quite unlike the polish of the published books. There are also some curiousities -- who (or what) for example is the odd 'third character' who appears in the last paragraph?
Meanwhile the castle rolled. Great walls collapsed, one into another, sometimes with a roar of dust, sometimes with no sound. The colours of the tracts were horrible. The vilest green. The most hideous purple. Here the foul shimmering of fungi - there a tract of books alive with mice. In every direction vistas opened, so that Gertrude standing at the little window of a high room, would seem to command a world before her eyes, though her eyes were out of focus. It had become a habit of hers to stand at this particular window, from which a world lay bare, a chowder of cats at her feet and her dark red hair full of nests.
Who else is there alive in this echoing world? And yet for all the collapse and decay, the castle seemed to have no ending. There were still the endless shapes and shadows, echoing the rides of stone.
While the Countess Gertrude moved about her home, it might be thought that she was in some kind of trance, so silent she was. The only sound coming from her hair in whose deep coils the small birds twittered. As for the cats, the swarmed about her like froth.
One day the massive Countess standing before the little window of her bedroom lifted her matriarchal head and brought her eyes into focus. The birds fell silent and the cats froze into an arabesque. And as she approached from the west, so Prunesquallor, his head in the air, approached from the east, and as he minces, he sang in a falsetto unutterably bizarre.
"Is that you, Prunesquallor?" said the Countess, her voice travelling gruffly over the flagstones.
"Why, yes," trilled the Doctor, breaking off in his own particular improvisation. "It most assuredly is."
"Is that you, Prunesquallor?" said the Countess.
"Who else," said her voice travelling across the flagstones.
"Who else?" cried the Doctor. "It assuredly is. At least I hope so." And Prunesquallor patted himself here and there, and pinched himself to make sure of his own existence.
CHAPTER 1 THE DESCENT FROM GORMENGHAST MOUNTAIN
With every pace he drew away from Gormenghast Mountain, and from everything that belonged to his home. That night, while Titus lay asleep in the tall barn, a nightmare held him. Sometimes as he turned in his sleep he muttered, sometimes he spoke out loud and with extraordinary strange emphasis. His dreams thronged him. They would not let him go.
It was early. The sun had not yet risen. Outside the barn the hills and the forests were hoary with cold dew, and blotched with pools of ice.
What is he doing here, the young man, 77th Earl and Lord of Gormenghast. This surely is a far cry from his home and his friends. Friends? What was left of them? As for his home, that world of fractured towers. What truth is there in its existence? What proof had he of its reality?
Sleep brought it fourth in all its guises, and as he turned again, he hoisted himself on his elbow and whispered "Muzzlehatch, my friend, are you then gone forever?"
The owl made no movement at the sound of his voice. Its yellow eyes stared unblinking at the sleeping intruder.
Titus fell back against the straw and immediately three creatures sidled into his brain. The first so nimble on his feet was Swelter, that mountain of flesh, his belly trembling at every movement with an exquisite vibration. Sweat poured down his face and bulbous throat in runnels. Drowned in his moisture, his eyes swam here no larger than pips. In his hand he carried as though a toy, a double- headed cleaver. At his shoulder stood something which was harder to define. It was taller than Swelter, and gave forth a sense of timber and of jagged power. But it was not this that caught the senses, but the sound of knee-joints cracking.
For a moment they beamed at one another, this dire couple in a mixture of sweat and leather-- and their mutual hatred settled in again, like a foul plant or fungi. And yet they held hands, and as they moved across the arena of Titus' brain they sang to one another.
Swelter in a fluted voice, and Flay reminiscent of a rusty key turning in a lock. They sang of joy, with murder in their eyes. They sang of love, with bile upon their tongues. Those tongues. Of Swelter's it is enough to say that it protruded like a carrot. Of Flay's that it was a thing of corroded metal.
What of the third character? The lurker in the shade of Swelter's belly? Its tongue was green and fiery. A shape not easily found. It was for the main part hidden by a brush of mottled hair. This third apparition, a newcomer to Titus' brain, remained in the shadow, a diminutive character who reached no higher than Swelter's knee-joint. While the other two danced, their hands joined, the tiny creature was content to watch them in their foul perambulations, until loosening their grip upon one another Swelter and Flay rose to full height upon their toes and struck one another simultaneously, and Titus in his dream twisted away from them.