Possible Clues:

• Unusual play — Act I nonsensical
• 'Abnormal, aberrant (8)'
• Uncharacteristic, a state bordering on bogus pity
• Unusual element of 'floaty' pi calculation
• A dreadful pity about the French revolutionary being deviant
• What a pity to get a hundred and a fifty in so unusual a way!
• Not class conscious perhaps of what¿s made of a lap around city
• Uncharacteristic year in capital abroad
• Unusual capital city ultimately abandoned
• Abnormal, aberrent.