Just unzip this file into the Descent directory. Start Descent as usual 
and start a new game and select Lupis Three as the mission.

к----------------------------------------------П
Г A NEW add-on level for the Registered DescentГ
ГллВВВВББББББББААААААААААААААААААББББББББВВВВллГ
Г                  Lupis3  v 1.0               Г
ГLupis Three takes you into the somewhat newly Г
Гinfested Lupis system. It is important to     Г
Гremember three things when playing this level:Г
Г                                              Г
Г1. Don't blow the reactor until you have seen Г
Г   the exit.                                  Г
Г                                              Г
Г2. Flairs can disclose even the most          Г
Г   transparent of enimies.                    Г
Г                                              Г
Г3. Baby spiders only take one single hit from Г
Г   a plasma gun to destroy.                   Г
Г                                              Г
ГThis level is excellent for individual or     Г
Гdeathmatch play. Large design and fully       Г
Гmultiplayer supported.Documentation for use isГ
Гincluded.                                     Г
ГллВВВВББББББББААААААААААААААААААББББББББВВВВллГ
Г           Created By Brett Russell           Г
Г            (brettr@interramp.com)            Г
Р----------------------------------------------й