Voyage to the Bottom of the Sea (1964)

S1E16 Hail to the Chief

After a serious fall, the President of the United States urgently requires surgery, but the procedure must remain confidential. Seaview is selected as the ideal location for the operation. Meanwhile, a cunning enemy agent impersonates the doctor who was supposed to perform the surgery, plotting to use a lethal radiological device against the Commander-in-Chief. The race is on to uncover her scheme before it's too late to protect the President. Will they manage to thwart her plan in time?