Tunnel 6

When Geraldine Halloran arrives at the Central Pacific end of track in the winter of 1866, she’s resolved not to be terrified. After all, she has a right to be there. She was hired on as regular telegraph operator, though they thought they were hiring a man. She’s the only other woman at Tunnel 6, except for Mrs. Strobridge, the superintendent’s wife. Tunnel 6 was said by some to be impossible. Nothing like it had ever been done. It was to be a railroad tunnel linking California with Nevada, over 1700 feet long and 6000 feet altitude, dug through solid granite using black powder, nitroglycerin, and more than 5000 Chinese laborers.

Geraldine begins to have second thoughts when it gradually becomes clear that someone is trying to sabotage the railroad. And also trying to kill the man she loves. 

Read this book because secrets may be revealed.