Instructions
You will need to have Half-Life installed on your machine. Make sure it's version 1.0.0.9 or greater.
Download the prisoner.zip file.
Unzip the file. Place the 13 .bsp files into your Half-Life maps folder which is probably called C:\SIERRA\Half-Life\valve\maps
Place the prisoner.bat file into the folder with the Half-Life executable which is probably called C:\SIERRA\Half-Life
Double-click prisoner.bat