In this episode, offender profiler Frank Black (Lance Henriksen) tracks two women who have escaped from prison; they believe that one of them is pregnant with a virginal conception.
Sonny inflicts fatal injuries the second guard in response before realizing Viti has survived, as the bullet was stopped by a badge on her stolen uniform.
Later, profiler Frank Black (Lance Henriksen) is called to investigate the breakout by prison warden Kellard (Ed Lauter).
They abandon the car, with the motorist tied in the back seat, before fleeing to a motel where it is revealed that Viti is pregnant.
Sonny and Viti visit a clinic for a sonogram but leave abruptly when they realize the guard they attacked died of his injuries.
Black and fellow Millennium Group investigator Peter Watts (Terry O'Quinn) learn that the sonogram revealed a placenta praevia, which could prove fatal during labor.
However, Handlen considered the ending of the episode to be too "neat and tidy", resolving a potentially profound development for the series in quite a perfunctory manner.
[7] Robert Shearman and Lars Pearson, in their book Wanting to Believe: A Critical Guide to The X-Files, Millennium & The Lone Gunmen, rated "In Arcadia Ego" one star out of five.
Shearman called the episode "uncharacteristically crass" and "simplistic to a fault", finding its characters much too one-dimensional to tell an effective story.