Lupin III Special 8: The Secret Of The Twilight Gemini

As one of Lupin's mentors lays dying in bed, he procures a small diamond, which, he claims is a key to the lost treasure of the Gelts -- a people who once were part of a now conquered empire. The diamond (called Twilight) leads Lupin and Jigen to Morocco, along with not only inspector Zenigata, but also, the head of Interpol. Lupin quickly becomes involved in much more than he bargained for, when a showdown erupts between the Gelts and an a faction headed by the son of the Geltish leader -- both of whom want the diamond for themselves.