 " 4 @-@ D " received mixed to positive reviews from critics . Robert Shearman and Lars Pearson , in their book Wanting to Believe : A Critical Guide to The X @-@ Files , Millennium & The Lone Gunmen , rated the episode four stars out of five . The two noted that , while the episode 's premise " doesn 't seem as well thought through " as Maeda 's past efforts , " 4 @-@ D " is " worth it " . Shearman and Pearson concluded that the episode " earns its stripes by at last restoring to the series a pulse . " Furthermore , they praised Gish 's performance , noting that she " finally [ is ] given a showcase that makes Reyes so much more than a New Age fanatic " . Christina Urban , in an editorial review of the ninth season in Barnes & Noble , praised the episode . Urban said it is " by far the best of the season " . Jessica Morgan of Television Without Pity awarded the episode a " B " . Morgan slightly criticized the episode 's resolution , writing that it " explained nothing . I mean , how do these other universes work ? " 
