 The writers and producers of " Q @-@ Less " developed the episode to show that DS9 was still connected to the Star Trek universe . To facilitate this idea , two TNG characters , Vash , played by Jennifer Hetrick , and Q , played by John de Lancie , returned to DS9 . Vash made her first appearance on TNG in the episode " Captain 's Holiday " , and then returned in " Qpid " ; Q had appeared in most seasons of TNG since the first season . TNG writer Hannah Louise Shearer , known for writing episodes such as " The Price " and " We 'll Always Have Paris " , also crossed over to DS9 . " Q @-@ Less " was the last Star Trek writing credit for Shearer . 
