g the muscles of his arms, failing altogether to get the weight of
his body on the oar. At the end of twenty minutes Priscilla gave him a
rest.

"There's no use our killing ourselves," she said. "The tide's under us.
It's a jolly lucky thing it is. If it was the other way we wouldn't
get home to-night. I wonder now whether the Kinsellas think you've any
connection with the police. You don't look it in the least, but you
never can tell what people will think. If they do mistake you for
anything of the sort it might account for their not wanting you to land
on Inishbawn."

"Why?"

"Oh, I don't know why exactly--not yet. But there often are things
knocking about which it wouldn't at all do for the police to see. That
might happen anywhere. There's an air of wind coming up behind us. Just
get in that oar of yours. We may as well take the good of what's going."

A faint ripple on the surface of the water approached the _Tortoise_.
Before it reached her the boom swung forward, lifting the dripping main
sheet from the water, and the boat slipped on.

"But of course," said Priscilla, "that idea of your being a policeman
in disguise doesn't account for their telling Miss Rutherford that there
was something on the island which it wouldn't be nice for a lady to
see. And it doesn't account for the swine-fever story that Joseph Antony
Kinsella told the spies."

"What was that?"

"Oh, nothing much. Only that his wife and children had come out all over
in bright yellow spots."

"But perhaps they have."

"Not they. You might just as well believe in Peter Walsh's rats. That
leaves us with three different mysteries on hand." Priscilla hooked her
elbow over the tiller and ticked off the three mysteries on the fingers
of her right hand. "The sponge lady, whose name may be Miss Rutherford,
one. Inishbawn Island, that's two. The original spies, which makes
three. I'm afraid we'll have to row again. Do you think you can, Cousin
Frank?"

"Of course I can."

"Don't be offended. I only meant that you mightn't be able to on account
of your ankle. How is your ankle?"

"It's all right," said Frank, "That is to say it's just the same."

No other favouring breeze rippled the surface of the bay. For rather
more than an hour, with occasional intervals for rest, Frank tugged at
his oar, bumped his back, and was struck on the side of the head by
the boom. He was very much exhausted when the _Tortoise_ was at length
brought alongside the