 The episode made use of the standing Enterprise sets, as well as those created for Degra's ship. Guest stars included those who had previously appeared as members of the Xindi Council, as well as several who are new to Enterprise, who appeared as members of the future Enterprise. Most scenes were filmed between February 3 and February 11, 2004, with an additional special effect shoot on February 13. Reviewers compared "E ²" to a number of several other episodes, including "Children of Time", "Deadlock" and "All Good Things ...". The Nielsen ratings received by the episode equated to a 3.3 / 5 % audience share.
