Big River caught Mr. Quack's quick
ear. As Mrs. Quack brought her head up out of the water, Mr. Quack
warned her to keep quiet. Noiselessly they swam among the brown stalks
until they could see out across the Big River. There was another little
splash out there in the middle. It wasn't the splash made by a fish; it
was a splash made by something much bigger than any fish. Presently
they made out a silver line moving towards them from the Black Shadows.
They knew exactly what it meant. It meant that some one was out there in
the Big River moving towards them. Could it be a boat containing a
hunter?

With their necks stretched high, Mr. and Mrs. Quack watched. They were
ready to take to their strong wings the instant they discovered danger.
But they did not want to fly until they were sure that it _was_ danger
approaching. They were startled, very much startled.

Presently they made out what looked like the branch of a tree moving
over the water towards them. That was queer, very queer. Mr. Quack said
so. Mrs. Quack said so. Both were growing more and more suspicious. They
couldn't understand it at all, and it is always best to be suspicious of
things you cannot understand. Mr. and Mrs. Quack half lifted their wings
to fly.

CHAPTER XXX

THE MYSTERY IS SOLVED

It was very mysterious. Yes, Sir, it was very mysterious. Mr. Quack
thought so. Mrs. Quack thought so. There, out in the Big River, in the
midst of the Black Shadows, was something which looked like the branch
of a tree. But instead of moving down the river, as the branch of a tree
would if it were floating, this was coming straight across the river as
if it were swimming. But how could the branch of a tree swim? That was
too much for Mr. Quack. It was too much for Mrs. Quack.

So they sat perfectly still among the brown stalks of the wild rice
along the edge of the Big River, and not for a second did they take
their eyes from that strange thing moving towards them. They were ready
to spring into the air and trust to their swift wings the instant they
should detect danger. But they did not want to fly unless they had to.
Besides, they were curious. They were very curious indeed. They wanted
to find out what that mysterious thing moving through the water towards
them was.

So Mr. and Mrs. Quack watched that thing that looked like a swimming
branch draw nearer and nearer, and the nearer it drew the more they
were puzzled, and the more curious they fe