What does the cryptic crossword clue "Intensity in shocking scenes with fire (10)" mean?

The definition is "Intensity". The wordplay uses an anagram. anagram of SCENES + FIRE = FIERCENESS; definition: "Intensity" The answer is Fierceness.

Intensity in shocking scenes with fire (10)

Telegraph Prize Cryptic #3049 | 3 Down | 2020-03-29 flower