Wilson is well aware that his frustration and fear and hatred of the Other was ridiculous. The Other seemed to mock him by acting like a caricature of Wilson, but no one seemed to notice — only Wilson did. Only Wilson seemed to be aware of the Other's "knowing and sarcastic" smiles. At any minute the school might realize what a joke the Other was making of Wilson — and yet it was unfair that they couldn't see through the charade he was making of Wilson.
One night, close to the end of Wilson's fifth year at the school, Wilson got out of bed, stole through "a wilderness of narrow passages" and found his rival sleeping. He had planned to play a practical joke on him for a long time. Carrying a lamp and pulling aside the curtains, Wilson saw lying there before him in a pool of bright light, a figure who made his breast "heave," his knees "totter," and his whole spirit become "possessed with horror." The figure was Wilson, and yet it was not Wilson. His rival did not look like this "in the vivacity of his waking hours," and Wilson wondered if what he now saw "was the result, merely of the habitual practice of sarcastic imitation?" With a shudder, he put out the light and left the school, never to return again.
After some months, he enrolled as a student at Eton, where he quickly "washed away the froth of [his] past hours" and dived into a sea of "thoughtless folly." He will not describe his life of dissolution at Eton, but he does tell us of one strange incident that happened. One night after a week of partying, he and a few of his friends were drinking and gambling in his apartment when, near morning, a visitor was announced. Wilson staggered through the feeble light of dawn to the vestibule and there he barely perceived a young man, dressed as Wilson was, in the latest fashion. The stranger strode up, seized Wilson by the arm and whispered "William Wilson!" in his ear. Wilson became sober in an instant. Then the stranger's manner and, above all, his voice uttering "those few, simple, and familiar, yet whispered syllables" sent him reeling. Before he could "recover the uses of [his] senses," the stranger was gone. For weeks, Wilson "was wrapped in a cloud of morbid speculation"; had all this really happened? He inquired about the other Wilson at Dr. Bransby's school and learned that the fellow left on the same day that Wilson himself did.
