Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "user.cfg" file in the game directory. Add the following lines to the file, then start the game and begin a new mission:

play
starting_mission 16

Alternately, install Dromed from the Goodies folder on Thief Gold disc one. Then, start Dromed and open mission 18. Press [Alt] + G after it loads to enter the game.