Possible Clues:

• Assist in state of stagnation
• This will 20 down if you don't go, sister, by the sound of it
• One of the family sat up during the stoppage
• Possibly assist when blood circulation is arrested
• 'Don't go and sound stagnated, little sister (6)'
• Secret police's arrest
• 'Little sister, don't go, by the sound of it, and be in stagnation (6)'
• 'Hang around, girl!', we say, in period of inactivity
• State of balance
• Secret police given seconds to make arrest