Tripwire

A former military policeman drifting through Key West as a pool digger and bouncer, pulled back into the world he walked away from.

A ruthless, hook-handed loan shark in New York with a Vietnam War past, who seizes his clients' businesses by threats and torture.

Co-owner of a struggling New York company that becomes a target of the villain's takeover.

A private investigator who comes looking for Reacher in Key West on behalf of a client.

The daughter of Reacher's old commanding officer, who is married and working in New York and wants Reacher to finish a task her father began.