Also in early April, James Donovan, U.S. negotiator, returns to Cuba to confer with Premier Fidel Castro for the further release of Bay of Pigs prisoners. The CIA attempts through an unwitting Donovan to foist a CIA-contaminated diving suit on Castro, as a gift by the Kennedy-appointed negotiator, in a failed effort to simultaneously assassinate Castro, scapegoat Kennedy, and sabotage a beginning Cuban–American dialogue.