BINARY STAR SYSTEMS THAT EMIT GAMMA-RAYS ARE EXTREMELY RARE. THEY REQUIRE THAT ONE OF THE "STARS" IS EITHER A BLACK HOLE OR A NEUTRON STAR AND THAT THIS INTERACTS WITH ITS STELLAR COMPANION IN SUCH A WAY THAT GAMMA-RAYS CAN BE PRODUCED. WE HAVE NOW DISCOVERED A NEW MEMBER OF THIS POORLY UNDERSTOOD CLASS OF OBJECT: 3FGL J1405.4-6119. THIS BINARY SYSTEM SHOWS MODULATION OF ITS GAMMA-RAY X-RAY AND RADIO EMISSION ON A 13.7 PERIOD WHICH WE INTERPRET AS THE ORBITAL PERIOD OF THE SYSTEM. USING NUSTAR AND SUPPORTED BY XMM WE WILL OBTAIN OBSERVATIONS OF THE X-RAY EMISSION AT TWO DIFFERENT ORBITAL PHASES. THE DATA RETURNED WILL ENABLE US TO INVESTIGATE THE PHYSICS DRIVING THE EMISSION AND ITS ORBITAL VARIABILITY.