No Exit by Taylor Adams

College student Darby is heading home to Utah for Christmas to see her dying mother when she's caught in a blizzard. Forced to get off the road by the bad weather, she ends up at a rest stop thinking she can wait out the storm and then be back on the highway. When she sees a girl locked in a cage in one of the other cars at the rest stop, she wonders which of the other four people trapped there are responsible. Soon, Darby finds herself fighting for both her life and the girl's in order to see justice done. No Exit is a white-knuckled thriller that's hard to put down, but it's not for the squeamish. Give to people who enjoy Harlan Coben and Greg Iles' 24 Hours.