Related Clues:

• Engineers put in that warning
• Menace at that place wasting energy
• E.g. I'll have you executed, Mad Hatter
• Religious education essential to anything but this menace
• Indication of danger
• Source of danger in hospital covered by doctor or nurse
• Blackmailer's tactic
• Danger that must include sappers
• Danger which catches engineers
• It is a menace when it is hot during an outing
• "Or else!" is one
• Menacing remark
• Potential danger which overwhelms some soldiers
• '... or I quit!,' e.g
• Negotiation tactic