Sweeper bot. Everybodies favorite non-vendor npc. HOWEVER, it is quite mysterious that its whistle suddenly started working in the cabal invasion. When the traveler was trapped by gary. Hmmmmmmm............. Also, sweeper starts with an s and has seven letters. Do you know what other destiny character starts with an s and has seven letters? SAVATHUN. Coincidence. I THINK NOT. Now i propose a theory that will change the destiny community forever. Sweeper bot is actually an exo in which savathun's conscioussness resides. Savathun, being so close to the traveler, could not even manage to whistle because she was weakend by the immense amounts of light concentrated in the tower plaza. But, when the traveler was trapped, when most guardians where off protecting innocents in the city, sweeper bot, or should i say Savathun, choose this moment to disappear and plan her invasion of the city with all the valuble intel sweeper gathered. We have been betrayed guardians. Edit: I am an idiot. Savathun has 8 letters.