Related Clues:

• Heading for stairs, step in room
• Parking garage slot
• Vacuum seen in sci-fi
• 'N,' in many assn. names
• "N," in many assn. names
• Origin of some invaders
• One of two gaps in 'mind the gap,' e.g
• Constituent of NASA
• Parking-lot spot
• It's between words ... or worlds
• Parking unit
• Room key
• Setting for many sci-fi movies
• Kirk’s “final frontier”
• Race venue of old?