: Steven, Elyse, Mallory, Jennifer, and baby Andrew. Why "12-1"?

The "12-1" might correspond to the 12th disc or file set in a complete series collection, with "1" being the first episode on that specific digital volume. Technical Note on .m4v

The "12-1" in your filename likely refers to the or a specific DVD/Volume numbering system rather than the season and episode number. In many digital collections: Season 4 is often grouped as the third or fourth "volume."

An file is a video container format developed by Apple, very similar to .mp4. These files are commonly used for content purchased or downloaded via the Apple TV app or iTunes . If you are having trouble playing it, ensure you are using a compatible player like VLC Media Player or QuickTime . PORTSMOUTH GASEOUS DIFFUSION PLANT EXPANSION

: The artistic, liberal freshman who challenges Alex’s worldview.