The Treos Dilemma, a Sci-Fi novel by William L. Lavell

Jace Ryan is captain of a ship that he and his crew have affectionately dubbed The Vindicator.  They're all fugitives on the run from The Company, a band of corporate despots who rule the Three Systems with an iron grip.  Ryan and his friends have all they can do to stay beyond the Company's reach and survive.

But Ryan is on another mission as well.  He was separated from his sister Jade when he was arrested, and since his escape has been searching high and low to get her back.  He gets a clue to her whereabouts when Tavion Karr, Vindicator's previous owner, gets out of prison and claims to have taken her hostage.  Ryan has no choice but to try to save her.  But Karr wants revenge for losing his ship, the Company's Commander Straker is never far away from capturing the Vindicator crew again, and before the mission is over, Ryan will even be forced to question the loyalty of one of his own.

This novel is the third book in the Vindicators series.  It's set a few months after Escape From Argus and ends a week before The Argenis Solution picks up the story.