S9·E18 Meta Fiction

Episode recap

Task: Write a 280-380 word episode recap for Supernatural S9E18 (Meta Fiction).
Constraint 1: Use only verifiable facts from the provided SYNOPSIS and SOURCES.
Constraint 2: No invented titles, names, dates, counts, awards, ratings, numbers, or plot points.
Constraint 3: If a detail is not in the material, omit it.
Constraint 4: Write original, neutral, encyclopedic prose in plain text.
Constraint 5: No markdown, no asterisks, no headings, no bullet points.
Constraint 6: Word count target: 280-380 words.
Synopsis: Castiel investigates the mass slaughter of angels and finds a lone survivor and an old friend. Sam and Dean capture Gadreel. Metatron begins the ending of his story.
Sources:
[1] TMDB: General info.
[2] Wikipedia: Series ran 15 seasons from Sept 13, 2005, to Nov 19, 2020. Stars Jared Padalecki as Sam Winchester and Jensen Ackles as Dean Winchester.
[3] IMDb: Cast/crew info.
[4] TMDB Cast: Sam and Dean lost their mother to a demonic force; father raised them as soldiers.
[5] Simple Wikipedia: Created by Eric Kripke. Horror, drama, fantasy, fiction.
Episode: S9E18 (Meta Fiction).
Castiel investigates mass slaughter of angels.
Castiel finds a lone survivor and an old friend.
Sam and Dean capture Gadreel.
Metatron begins the ending of his story.
Sam Winchester is played by Jared Padalecki.
Dean Winchester is played by Jensen Ackles.
The synopsis is extremely brief.
The sources provide context about the series (Sam and Dean Winchester, actors, genre, creator, dates).
The user wants 280-380 words.
Problem: The provided text contains very little information about the specific episode. If I strictly follow "Use only supplied facts" and "If the synopsis is sparse, stay concise rather than guessing," I cannot reach 280 words without repeating myself or adding fluff, which violates the "encyclopedic prose" and "never invent" rules.
Wait: The prompt says "If the synopsis is sparse, stay concise rather than guessing." This is a direct instruction to prioritize accuracy over word count if the source material is insufficient. However, the prompt also sets a word count range (280-380).
Conflict Resolution: In professional archiving, if the source material is insufficient