When Sidney would not hand over the jewels to the Kanaka, as the latter wanted him to, Cockatoo, already prepared with the window cord, which he had silently taken from the blind, sprang upon the unfortunate assistant and strangled him.

Cockatoo told this to his horrified master, and wanted him to come back to hide the corpse in the packing case.
Braddock refused, and then Cockatoo told him that he would throw the jewels--which he had taken from Sidney's body--into the river.

The position of master and servant was reversed, and Braddock was forced to obey.
"The Professor slipped silently ashore and into the room.

The two men relighted the candle and pulled down the blind.

They then placed the corpse of Sidney in the packing case, and screwed the same down in silence.