This is the first and only "Voyager" episode to feature the Utopia Planitia Fleet Yards. The fleet yards were seen previously in a picture in Parallels (1993) and as a holographic simulation in Booby Trap (1989). Utopia Planitia would be seen again in three episodes of Star Trek: Picard (2020).
This episode features the return of not only Captain Braxton, whose previous appearances were in Future's End (1996)/Future's End: Part II (1996), but also Lieutenant Joe Carey, who was last seen in State of Flux (1995). Carey's scenes here, however, take place before Voyager is lost in the Delta Quadrant. He returns in Fury (2000) but his scenes in that episode also take place in the past. He is not seen again in the present (namely, 2378) until Friendship One (2001), his final appearance.
Bruce McGill (Braxton) previously played a similar role in the film Timecop (1994), in which he was the supervisor of a team of agents charged with restoring and protecting the timeline.
The 29th century phaser that Seven of Nine uses against Braxton is of the same type seen in possession of Henry Starling's assistant Dunbar in Future's End (1996)/Future's End: Part II (1996) during the phaser fight outside the Griffith Observatory in Los Angeles in 1996.