God's Thunderbolt:

December 1863. Daniel Stark, New York lawyer and radical abolitionist, has come to Alder Gulch to get enough gold to redeem his family from disgrace after his father’s suicide revealed that he had gambled away his clients’ assets. But as travelers are robbed and murdered, Dan realizes that he will likely not survive. Then a friend is murdered, and Dan successfully prosecutes the suspected murderer in miners court.

After testimony during the trial reveals a criminal conspiracy operating in the area, Dan joins a Vigilante group that unites Union and Confederate sympathizers in establishing the law where ruffians rule and murder is tolerated. But as the Vigilantes close in on the conspirators, Dan, now the Vigilante prosecutor, faces the horrible prospect of hanging both a friend and the husband of the woman he has come to love.