Clue: Imagine seeing a criminal stealing Victoria's crown (8)
Answer: ENVISAGE
Explanation: Definition: Imagine
An envelope ('stealing') of V ('**V**ictoria's crown') in ENISAGE, an anagram ('criminal') of 'seeing a'. 'stealing' seems a strange envelope indicator, but the clue makes sense if read as "Taking V from ENVISAGE gives an anagram of 'seeing a' ".