Possible Clues:

• Like a bright night
• Doctor on-line: it is the opposite of 16
• Bright at night
• Like a romantic evening
• Illuminated at night
• Naturally illuminated at night
• To be found in the general area of Thackeray's Barry Lyndon
• Like a romantic night
• Like the forest in 'A Midsummer Night's Dream'
• May be seen nocturnally, if this fluid motion is out of line