Vaatrik Pallra was a Bajoran, the widow of chemist and collaborator Vaatrik, both of whom lived on Terok Nor during the Cardassian Occupation of Bajor. She and Quark had become friendly during the occupation.
Pallra denied that she killed her husband, although Constable Odo was convinced she did. Her husband was killed by the resistance. Kira Nerys had to kill Vaatrik when he caught her searching his shop for a list of collaborators. Vaatrik had been selling his people out to the Cardassians. After the occupation of Bajor was over, Mrs. Vaatrik asked Quark to get a box with a list of names that was in her husband's old shop. She used this list, which was the names of fellow collaborators in it, to blackmail them for money. After Quark got the list for her, she had Trazko try to kill him. She was arrested by Odo for the attempted murder and blackmail. (DS9: "Necessary Evil")