That evening the four chums spent in the barn back of Fenn's house. There was considerable hammering and pounding and fitting together of planks, boards and boxes.
The next afternoon the four boys worked hard perfecting their arrangements. There were four entrances to the barn, consisting of large sliding doors in front and rear, and a small door that gave entrance to the stable proper. The way to each of these was so arranged that any persons passing along them would have considerable trouble in reaching the structure. It was impossible to walk along them and not step on a 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.
"I don't believe so," replied Fenn. "I've put extra hooks and bolts on, and there are heavy bars to the big front and rear doors."
Saturday evening the materials for the spread were duly delivered at the barn. Half a dozen boys volunteered as guards. It was arranged that the members of the nine and their friends, numbering in all about twenty-five, should come in through the cow stable door.