What does the cryptic crossword clue "Review top secret revelation's source after decoding (10)" mean?

The definition is "Review". The wordplay uses an anagram. anagram of TOP SECRET R = RETROSPECT; definition: "Review" The answer is RETROSPECT.

Review top secret revelation's source after decoding (10)

Times Cryptic #28617 | 1 Down | 2023-05-31 flower