Related Clues:
- Period of imminent danger
- Siren's signal right, altered wrongly
- State of readiness for imminent threat
- Alert status
- 'Impending danger' signal
- Communist later beaten up in heightened security state
- High state of readiness
- Severe 1 dn
- Alarm about depression: recovery then starts
- Severe warning
- High crisis level
- State of high readiness
- Highest level of warning
- Engineers by valley having radio telegraphy to give warning
- Emergency keeps Labour on the qui vive