Twice Held Hostage

Gold!
Rock City, a small isolated town located near timberline, has a gold mine. Crystolians from the planet Argos need gold.
Recent college graduate, Derek Lang, is fired by his gold-lusting boss, Captain De Prive, who then schemes how he can take over Rock City's mine. Derek, angry with De Prive and also bitter because God did not save his wife's life, returns to Rock City. When he learns his town has decided to loan gold to aliens, he shows hostility toward Laird, the Crystolian leader, and his son, Raynor, who commands the spaceships that brought their miners. Raynor earns his trust and friendship while they prospect to locate a site for an Argos mine.
A trip to Argos restores Derek's faith in God. During his three years there, De Prive, along with his corrupt friends, amass enough money to pull off De Prive's scheme.
Their loan paid, Crystolians, who touch down to visit, find strangers mining, and the townspeople gone, including Derek, his wife, Angelina, and their son, Robin.
Where are they?
From the author of Lives Intertwined.