T'Pol tells Captain Archer there is an old Vulcan saying, "One man can summon the future". This is a nod to the original Mirror, Mirror (1967), in which the "alternate" Spock tells Captain Kirk the saying of Mirror Vulcans; "One man cannot summon the future".
This was the first episode to feature a Rigellian vessel and the first to feature the appearances of the founding members of the Federation, Humans, Vulcans, Andorians, and Tellarites, together since Journey to Babel (1967) and Whom Gods Destroy (1969).
One of the Romulans who remotely controls of the camouflage ship is Admiral Valdore. He shares the same name as Commander Donatra's warbird Valdore from Star Trek: Nemesis (2002). It is likely that the warbird was named in honor of the Admiral.
T'Pol calls Travis Mayweather "Travis" for the first time.
This episode marks the first appearance of Remans in any Star Trek series; in this case, two of them serve as Senator Vrax's bodyguards. The Reman species first appeared onscreen in Star Trek: Nemesis (2002).