S9·E5 Dog Dean Afternoon

Episode recap

Task: Write a 280-380 word episode recap for Supernatural S9E5 (Dog Dean Afternoon).
Constraints:
Use ONLY verifiable facts from the provided SYNOPSIS and SOURCES.
No invented titles, names, dates, counts, awards, ratings, box-office, or plot points.
If a detail is not in the material, omit it.
Style: Original, neutral, encyclopedic prose, plain text.
No markdown, no asterisks, no headings, no bullet points.
Word count: 280-380 words.
Synopsis: Dean uses a spell to track a killer. The spell allows him to speak with a German Shepherd, the only witness. The spell causes Dean to start acting like a canine.
Sources:
[1] Supernatural (2005) is a TV-14 Drama, Mystery, and Sci-Fi & Fantasy series.
[2] Created by Eric Kripke. Broadcast on The WB and later The CW for 15 seasons (Sept 13, 2005, to Nov 19, 2020). Follows brothers Sam (Jared Padalecki) and Dean Winchester (Jensen Ackles).
[4] Sam and Dean Winchester lost their mother to a demonic supernatural force. Their father raised them to be soldiers to kill paranormal evil.
Wait, the synopsis is very short. The prompt asks for a 280-380 word recap.
The synopsis only provides: Dean uses a spell to speak to a German Shepherd (witness to a killer). The spell makes him act like a dog.
The sources provide: Series background (Sam and Dean Winchester, Eric Kripke, 15 seasons, etc.).
Problem: If I strictly follow "Use only supplied facts" and "If the synopsis is sparse, stay concise rather than guessing," I cannot reach 280-380 words without repeating myself or adding fluff, which violates the "neutral, encyclopedic prose" and "never invent" rules.
Let's look at the synopsis again: "To track down a killer, Dean uses a spell which allows him to speak with the only witness, a German Sheppard. However, he soon discovers that everything is going to the dogs when the spell starts making him act like a canine as well."
The sources provide context about the series: It is an American dark fantasy television series created by Eric Kripke. It follows brothers Sam Winchester, played by Jared Padalecki, and Dean Winchester, played by Jensen Ackles. The series aired on The WB and The CW for 15 seasons between September 13, 2005, and November 19, 2020. The brothers were raised by