Quite unconscious that two small spies had resolved to keep her movements under surveillance, Netta slipped away from her friends after dinner, and returned to the classroom. It did not take her long to finish her task; she had soon fastened her nineteen envelopes, then, concealing them in an exercise-book cover, she hurried downstairs. Miss Roscoe's study was still empty, and nobody seemed about, for Netta never noticed the cautious pair who were dodging and watching in her rear as cleverly as a couple of young detectives. After a hasty glance round the room she advanced to the Principal's desk, and deeming herself quite unobserved, rapidly exchanged the pile of envelopes there for those which she had brought with her. She gave one look of satisfaction at the substituted set--they were such an excellent imitation--and bore off the genuine ballot to the Fifth Form room. Ida and Peggie, with breathless interest, followed, and saw her putting the stolen goods into her desk; then, having witnessed as much as they considered necessary, they flew in hot haste to lodge the information with their own Form mistress. Miss Broughton, amazed at what they told her, sought Miss Roscoe, who summoned Ida and Peggie, and listened attentively to their story. "This must be enquired into promptly," she declared. "Come with me at once to the Fifth Form." The girls had just assembled for afternoon school when the Principal entered, bearing the substituted pile of envelopes, and accompanied by Ida and Peggie. For Miss Roscoe to arrive at such a time was an absolutely unprecedented occurrence. A dead silence at once reigned. Everybody wondered what had happened, and why Miss Roscoe should have brought the two children with her. The headmistress walked straight up to Netta's seat. "Netta Goodwin," she said, "such an extraordinary incident has just been reported to me that I feel it is my duty to investigate it immediately. I wish to see what you have here," and, throwing up the lid, she began to investigate the contents of the desk. Netta gave a gasp as if an earthquake had opened at her feet, and turned deathly white. She did not venture to say a word. All in the room waited in mute suspense, realizing that the matter must be of vital importance. With a sad face Miss Roscoe drew out the nineteen envelopes and compared them with those which she held in her hand. "I have a very serious charge against you, Netta Goodwin," she said sternly. "You were observed in the act of taking these letters from my study, and substituting a similar set which you had yourself written. Ida Bridge and Peggie Weston can testify that they themselves witnessed your deed. I have a strong suspicion of your motive, and I am going to open the envelopes to ascertain if I am correct." Putting each pile separately, Miss Roscoe rapidly tore open the two ballot sets, and glanced over them.