Lt. Orso is the lieutenant and bodyguard of General Medrano. He is first seen in Port-au-Prince, Haiti where Medrano met with Dominic Greene. Here they took Camille Montes by the order of Greene, but Bond saved her and shipped away.
Later Orso is present when Medrano meets with one of his henchmen, Carlos, in the Atacama Desert to finalize the coup. At the hotel, Greene arrives and Medrano negotiate their terms. Greene then finally reveals his true plans: now that he controls the majority of Bolivia's water supply, Greene forces Medrano to accept a new contract that makes Greene Planet Bolivia's sole water utility company at significantly higher rates.
When the General shows resistance to Greene's terms, Greene notes that to Quantum, Medrano is completely expendable and if he refuses to sign he will "wake up... with [his] balls in [his] mouth... and [his] willing replacement standing over [him]." Threatened into submission by Greene, he signs. To vent his frustration he tries to rape his maid. Orso and one of the General's soldier are guarded his room. But Camille - who managed to infiltrate the building along with Bond - shot the soldier and Orso in his chest. After Orso survived it Camille hit him and droped him down through the railing to death.