Jennifer Grünwald worked at the New York Public Library in the foreign language department. A strange man speaking in an undetermined foreign language approached the 21-year-old Jennifer at work, as a hazy "drug-like" feeling washed over her. She heard the stranger speak to her in her mind in English, compelling her to follow him outside. In a back alley across from the library, Grünwald was rendered into a cloudy state of mental submission. The stranger, apparently a vampire, bit Grünwald on the neck. Grünwald remembered nothing else until awakening in her apartment that night, alone, disoriented, and apparently unharmed save for the two bite marks. She was scared to return to work, and embarrassed to go to the police. Yet, feeling she had somehow changed, Grünwald was compelled to understand what had happened to her. She agreed to allow Daily Bugle reporter Ben Urich to interview her. However, Bugle publisher J. Jonah Jameson refused to print Urich's article.
Urich returned to Jennifer's Brooklyn apartment with additional questions. Jennifer appeared dramatically different from the previously seen modestly dressed library worker. She aggressively kissed Urich and bit his neck with pointed canine teeth. Urich failed to return home that night and was absent from work the next day. Peter Parker, who, as Spider-Man, had previously encountered what appeared to be a vampire in Manhattan, went to Jennifer's apartment to search for Urich. There, Grünwald fought a vampiric wolf for possession of the unconscious body of Urich. Spider-Man clashed with the wolf, when Morbius appeared asking Spider-Man to leave. She was killed in the ensuing fight when Morbius staked her through the heart saying he was sorry he couldn't save her.
