As silently as shadows Dave and Phil followed the money-lender's son to the shed. Once Nat looked around to see if the coast was clear, and the followers promptly dropped down behind a lilac bush. Reassured, Nat entered the shed, and Dave and Phil tiptoed their way up and got behind the open door. The hired help were in the kitchen, so the shed was empty. On the floor stood an ice-cream freezer full of home-made ice-cream, and on a shelf rested several freshly baked cakes, all covered with chocolate icing, set out to harden. "Now I'll fix things," Dave and Phil heard the money-lender's son mutter. "Salt in the cream and salt in the layer cakes will do the trick! Some of the boys and girls will think they are poisoned!" Nat took up a bag of salt that was handy,--used for making the cream,--and proceeded to open the can in the freezer. Dave watched him as a cat does a mouse. Just as Nat was on the point of dumping some of the salt into the ice-cream he felt himself jerked backwards. The salt dropped to the floor, and Nat found himself confronting Dave, with Phil but a few steps away. "You contemptible rascal!" cried Dave, his eyes flashing. "Why--I--er----" stammered the money-lender's son. He did not know what to say. "Going to spoil the cream, eh?" came from Phil. "It was a mighty dirty trick, Nat." "On a level with what you did to Professor Potts," added Dave. "I--er--I wasn't going to do nothing!" cried Nat, with little regard for grammar. "I--er--I was looking at the ice-cream, that's all." "A poor excuse is worse than none," answered Dave, grimly. "You were going to put salt in the cream and spoil it, you needn't deny it." "See here, Dave Porter, I want you to understand----" "Don't talk, Nat, we know all about it," broke in Phil. "You planned to come here yesterday, and we can prove it. We were on the lookout for you." At this assertion the face of the money-lender's son changed. He grew quite pale. "I haven't time to waste on you--I want to enjoy this party," said Dave. "Come along with me." "Where to?" demanded Nat. "I'll show you," answered Dave, and caught the money-lender's son by the arm. "Catch hold of him, Phil, and don't let him escape." CHAPTER V AT NIAGARA FALLS "See here, I want you to let me alone!" stormed Nat Poole, and he tried to jerk himself free. "Listen, Nat," said Dave, sternly. "If you make a noise it will be the worse for you, for it will bring the others here, and then we'll tell about what you tried to do. Maybe Mrs. Wadsworth will call an officer, and anyway all the girls and the boys will be down on you. Now, if you want Phil and me to keep this a secret, you've got to come along with us." "Where to?" grumbled Nat, doggedly. "You'll soon see," returned Dave, briefly, and with a wink at his chum.