The hero of the story is a Venetian, named (for some unknown reason)
Ivan di Sorno. So far as I ascertained, he is the entire house of Di
Sorno referred to in the title. No other Di Sornos transpired. Like
others in the story, he is possessed of untold wealth, tempered by a
profound sorrow, for some cause which remains unmentioned, but which is
possibly internal. He is first displayed "pacing a sombre avenue of ilex
and arbutus that reflected with singular truth the gloom of his
countenance," and "toying sadly with the jewelled hilt of his dagger."
He meditates upon his loveless life and the burthen of riches. Presently
he "paces the long and magnificent gallery," where a "hundred
generations of Di Sornos, each with the same flashing eye and the same
marble brow, look down with the same sad melancholy upon the
beholder"--a truly monotonous exhibition. It would be too much for
anyone, day after day. He decides that he will travel. Incognito.

The next chapter is headed "In Old Madrid," and Di Sorno, cloaked to
conceal his grandeur, "moves sad and observant among the giddy throng."
But "Gwendolen"--the majestic Gwendolen of the balcony--"marked his
pallid yet beautiful countenance." And the next day at the bull-fight
she "flung her bouquet into the arena, and turning to Di Sorno"--a
perfect stranger, mind you--"smiled commandingly." "In a moment he had
flung himself headlong down among the flashing blades of the toreadors
and the trampling confusion of bulls, and in another he stood before
her, bowing low with the recovered flowers in his hand. 'Fair sir,' she
said, 'methinks my poor flowers were scarce worth your trouble.'" A very
proper remark. And then suddenly I put the manuscript down.

My heart was full of pity for Euphemia. Thus had she gone a-dreaming. A
man of imposing physique and flashing eye, who would fling you oxen here