Possible Clues:

• Insurgent — involving dramatic change
• New relationship originally developing
• Possible Trotskyist doing the rounds?
• Voyeur on trial, dreadfully subversive
• It could describe wheel turning red, perhaps
• Rebellious sweetheart returning by train, you suspect
• Radically new
• Note your rival — somehow radically different
• Rebellious
• *Changing gradually