Related Clues:

• They turn fly enough to get their knife into you like this
• Wound up for flight
• Do they turn dotty at night with a knife?
• Take a knife to the fly-by-nights up there
• They turn out at night to use the knife
• Get your knife into the fly-by-nights on the way back
• With aid of a knife you can make them go up at night
• Get your knife into them at night up there
• If you get your knife into them they come out backwards at night
• They're fly enough to come back to drive the point home
• They come back at night with a knife
• The fly-by-nights come back in a piercing way
• Do the fly-by-nights return to get their knife into you?
• They might come back by night with a dagger (4)
• Take a knife to the fly-by-nights back there