How was Khartoum killed? And how was his head placed in Woltz's bed?
He was fed Connie's cooking.
The novel hints that it was an inside job, which is what made Woltz come around. Nothing in the novel or the film says the horse was killed the same night that Tom had dinner with Woltz.
Ntra la porta tua lu sangu � sparsu, E nun me mporta si ce muoru accisu... E s'iddu muoru e vaju mparadisu Si nun ce truovo a ttia, mancu ce trasu.