. "\"Reciprocity\" is the eleventh episode of the third season of the American science fiction drama television series Fringe, and the 54th episode overall. In the episode, the Fringe division follows a chain of shapeshifter murders as the assembly of the doomsday device nears completion. Ryan McDonald and Charles Parnell guest starred.Co-executive producer Josh Singer wrote \"Reciprocity\", his seventh such credit for the series."@en . . . "11"^^ . . . "3"^^ . "2011-01-28Z"^^ . . . "Reciprocity"@en .