attacking force moved away along a fence until the rear of the fort was
gained. Then, with another cheer, all set out for the fort.

It was a grand rush and soon the air was once more filled with
snowballs, much to the delight of the spectators, who began to cheer
both sides.

"Oh, I hope they get into the fort this time," said Nan.

"I hope they don't," answered another girl, who had a brother in the
fort.

Inside the fort the boys were having rather a hard time of it. They were
close together, and a snowball coming over the walls was almost certain
to hit one or another. More than this, the pile of snow around the flag
was growing small, so that the flag was in great danger of toppling
over.

Up the two sides of the hill came the invaders, Bert leading the
detachment that was to attack the rear. He was hit again, but did not
falter, and a moment later found himself at the very wall.

"Get back there!" roared a boy from the fort and threw a large lump of
soft snow directly into his face. But Bert threw the lump back and the
boy slipped and fell flat. Then, amid a perfect shower of snowballs,
Bert and two other boys fairly tumbled into the fort.

"Defend the flag! Defend the flag!" was the rallying cry of the fort
defenders, and they gathered around the flag. The struggle was now a
hand-to-hand one, in which nothing but soft snow was used, and nearly