weakness, exhaustion,
should overtake them, before their scanty stock of provisions should
fail? Yet no lingering, maddening agonies of hunger or thirst should
attend their dissolution. Death would be easy and swift, and, above
all, would involve no separation. Both spoke truly in denying the grim
King his terrors.

The sun hung like a ball of fire in the unclouded blue of the heavens;
the sea was of that translucent green so inseparable from the tropics.
Mona, who had been intermittently sleeping, awoke to find herself alone.
An affrighted cry escaped her; and but that she was secured to the
ring-bolt she would have fallen into the sea.

"Love! love! where are you?"

"Here. Don't be alarmed, my dearest," was the soothing reply. "I have
been swimming a little, as before. I thought you had been under water
long enough."

For the raft, relieved of his weight, was now floating level with the
surface. The dews of the tropical night, as well as the soaking effect
of her long immersion, had given way to the potent rays of the sun, and
Mona felt quite warm and dry. Still, with it she felt a shivering
feeling which was ominous, together with a languor and depression such
as she had not hitherto shown. The lustre, too, had gone out of her
eyes, leaving them dull and heavy. Was it the beginning of the end, of
failing vitality, of final exhaustion?

Upon her companion and protector, too, the strain was beginning to tell,
nay, as he recognised to himself, was much more than beginning. Pale,
and hollow-eyed, he seemed to be putting forth a good deal of effort,
swimming as before, with one hand upon the hatch. With the weakening of
their bodily state a reaction had set in, dispelling the exaltation of
the day before. Both seemed to recognise the imminence of a grim
alternative--an early rescue, or a speedy end.

And now, as he swam thus, Roden's glance lit upon an object the sight of
which caused his blood to tingle in a curdling, creepy thrill, a small
object, dark, wet and glistening; and a great horror came upon him, for
he knew that object well. _It was the triangular dorsal fin of a
shark_.

Here was a new and truly appalling peril. Strange that up till then
this form of it had hardly occurred to him. Infested as the tropical
seas are with these horrible creatures, yet from the swiftly moving
steamer none had hitherto been sighted. In all the excitement of
getting clear of the sinking ship, in the hour