Related Clues:

• Black cat crossing one's path, e.g
• Harbinger literary mariner raised
• Sign captain up
• Albatross in 'The Rime of the Ancient Mariner,' e.g
• Full moon or dark clouds, maybe
• What a mystic might look for
• Sign from on high
• Sign for an oracle
• A shooting star, by some accounts
• Sign; portent
• The Grim in 'Harry Potter and the Prisoner of Azkaban,' e.g
• Fortune-teller's sign
• Forewarning, of a kind
• Sign of impending doom
• Sign here, people!