I'm on my first play-through (so, please no spoilers). My character is through-and-through a Railroad agent and believes in Synth Rights (this is a role-playing game, after all).
I find it, from a role-playing perspective, problematic that my character has to
capture a synth who wants to live in a raider group
in order to proceed with the Railroad and
free all synths from the Institute.
But when I try to complete 'Underground Undercover' at some point Z1 asks me to
continue to work with Father for now.
And there is only one option to doing so: 'Synth Retention' — Which I refused to complete before as it would be out-of-character.
Am I overlooking a path?
Best Answer
Actually Synth Retention is one of the steps in completing Underground Undercover
http://fallout.wikia.com/wiki/Underground_Undercover
The link above shows all the events that happens leading to the completion of the entire quest line, so essentially the answer is no, you must do the Synth Retention step in order to finish the quest line