But Melinda usually concealed her thoughts behind an expressionless look .
Melinda was aware of her risks as a collaborator to her husband ; two months earlier , Julius and Ethel Rosenberg had been executed for spying .
Melinda usually concealed Melinda 's thoughts behind an expressionless look .
Melinda was aware of her risks as a collaborator to her husband ; two months earlier , Julius and Ethel Rosenberg had been executed for spying .