Just unzip this file into the Descent directory. Start Descent as usual 
and start a new game and select Lupis1 as the mission.

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³ A NEW Descent replacement level for Level 1  ³
³ÛÛ²²²²±±±±±±±±°°°°°°°°°°°°°°°°°°±±±±±±±±²²²²ÛÛ³
³                  Lupis1  v 1.0               ³
³Lupis One takes you into the newly infested   ³
³Lupis system. This level is full of tricks and³ 
³puzzels to be figured out. Remember, all may  ³
³not be what it seems in this system. Fly      ³
³everywhere, but look out for traps!           ³
³Large design and fully multiplayer supported. ³ 
³Documentation for use included.               ³
³ÛÛ²²²²±±±±±±±±°°°°°°°°°°°°°°°°°°±±±±±±±±²²²²ÛÛ³
³           Created By Brett Russell           ³
³            (brettr@interramp.com)            ³
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