The eleven Indians first stole a few sailors' knives, which was fairly easy to do, and then they manufactured the singular weapon still in use on the plains of the Argentine and which Midshipman Morris described as follows:
They were secretly employed in cutting out thongs from raw-hides, to the ends of which they fixed the double-headed shot of the small quarter-deck guns. This, when swung round their heads and let fly, is a dangerous weapon and, as already observed, they are extremely expert with it. An outrage committed on the chief himself, precipitated the execution of his daring enterprise; for one of the officers, a brutal fellow, having ordered him aloft, of which he was incapable of performance, then, under pretence of disobedience, cruelly beat him and left him bleeding on the deck.
It was a day or two after this, in the cool of the evening, when the Spanish officers were strolling upon the poop, that Orellana and his ten companions came toward them and drifted close to the open doors of the great cabin in which Admiral Pizarro and his staff were lounging, with cigars and wine. The boatswain roughly ordered the Indians away. With a plan of action carefully preconceived, the intruders slowly retreated, but six of them remained together, while two moved to each of the gangways, and so blocked the approaches to the quarter-deck.