though I must leave you, you will
not be left alone, either by night or by day. While you are awake you
will be protected by a beautiful white cat that I shall send to you,
named Tom; and while you are asleep your fairy aunt will keep watch
over you; you will not see her, but you will know that she is with you
by your pleasant dreams. Only at one hour of the day will you be left
unguarded, and that is the hour before sunset. At that hour Tom will
have to be away, and your fairy aunt will not yet have arrived, so you
must be very careful of yourselves. You will, I hope, try always to
be good children; but in the hour before sunset you must try
twenty-four times harder than ever. Nobody knows what may happen when
a little child does wrong; but there is great danger that the sun
might catch fire and the moon freeze up. So, once more, my darlings,
be very careful; for every hour is as long as it is short, but the
hour before sunset is the longest and the shortest of all.'

The children promised to remember; and their mother kissed them and
went away. The same day Tom the Cat arrived. A beautiful big cat he
was, with deep soft fur, round yellow eyes, and a tail as thick as a
feather duster. He was also the sweetest-tempered cat in the world, so
that the children lived with him several years without even so much as
suspecting that he had such a thing as a claw about him. He could purr
as comfortably as the hopper of a windmill; and he took care of the
children better than a dozen nurses would have done. But an hour
before sunset every day he always disappeared, and only came back
again when the last bit of the sun had gone out of sight. Then he put
the children to bed, and purred outside their window until they fell
asleep; and as soon as that happened in floated the Fairy Aunt, to
kiss their closed eyelids, and to hover beside their beds and whisper
in their ears all manner of charming stories about Fairyland, and the
wonderful things that were to be seen and done there. But early in the
morning, just before they awoke, she would kiss their eyelids once
more and flit away out of the round window; and the white cat, with
his yellow eyes and his thick tail, would come purring comfortably in
at the door.

One day, however (the unluckiest day in the whole year), Hilda,
Harold, and Hector went out to play as usual on the round lawn in the
centre of the garden. It was Rumpty-Dudget's birthday--the only day in
the whole year on w