 The episode 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 five stars out of five , calling the premise " Dexter a decade early . " The two concluded that " the sympathy that Donella gives Rob as he shows his true colours is very touching . [ ... ] The final moments [ of the episode ] are a typically smart touch to this neglected gem of a story . " Paul Goebel of TV Squad listed Rob Roberts among his favorite X @-@ Files monsters . Rich Rosell from Digitally Obsessed awarded the episode 3 @.@ 5 out of 5 stars and wrote that the episode features a " great setup , but the climax leaves the usual open @-@ ended questions . " Zack Handlen on The A.V. Club called the episode " perfectly acceptable " and awarded it a " B + " . He was pleased with the episode 's unique format , calling it a " good gimmick " that made an otherwise " forgettable at best " episode — had it been constructed in the typical fashion of The X @-@ Files — into a memorable one . He was also positive towards the episode 's use of humor , noting that it " is very much on target " . Handlen , however , felt that the story showed the series ' tiredness and did not possess much suspense to keep the watcher completely engaged . 
