Clue: Work like 'The Raven'? Put in 'Always' and 'Nevermore', say (9)
Answer: OPPOSITES
Explanation: Definition: 'Always' and 'Nevermore', say
A charade of OP ('work') plus POSITES, an envelope ('in') of SIT ('put') in POE'S ('like The Raven' – a reference to Edgar Allen Poe's poem)