Related Clues:

• Sent smoke signals, maybe
• Tipped off
• Warned
• On one's toes
• Gave a heads-up to
• Informed
• On guard
• Let know
• Cautioned
• Gave information to
• Gave a warning
• Added music to, as in a play
• Forewarned
• Notified of danger
• Put on guard, forewarned