board, so fixed that it would tumble a box on the head of the enemy,
precipitate the boys into a packing case, or upset a big pile of planks.

The fourth entrance to the barn was in the basement through an old cow
stable, long unused. The door had not been opened in a number of years,
and the hinges were rusty.

However, the four chums oiled the door so it would work easily, cleared
away a lot of rubbish and then had a means at hand of getting into the
barn of which they felt sure none of the conspirators knew. That the
Upside Down boys were aware of the other entrances Fenn was sure, as
several of the first-year pupils had been seen about the barn Monday.
They did not, however, the chums thought, know of the traps.

Meanwhile preparations for the dinner went on. The food was
purchased from a caterer in town, and was to be delivered at the barn
Saturday evening.

The chums arranged to have it taken in through the large front doors, the
traps leading to them having been temporarily removed. After the victuals
were safely stowed away it was planned to have a guard of boys constantly
on hand inside the barn to protect them. The rumor of the threatened
attack on the spread was known to all the nine now.

"I rather guess they'll have all the trouble they want before they play
any tricks on us," said Bart, as he surveyed the defenses.

"Can they break in the doors, in case any of them get past the traps?"
asked Ned.