This is often done to ensure the file plays on standard devices like smart TVs or mobile phones that may not support MKV subtitles or audio tracks.
The extension .mkv.mp4 suggests the file was likely or renamed from a Matroska Video (MKV) container to an MP4 format. Mind_Swap_Epi5.mkv.mp4
Usually, these files are encoded in 720p or 1080p , though the dual extension can sometimes indicate a corrupted header if the file fails to open. Review: Star Trek: Strange New Worlds, "Spock Amok" This is often done to ensure the file
In many "mind swap" narratives, Episode 5 is where the antagonist gains control of a protagonist's body to commit a crime or sabotage a mission, leaving the hero trapped in a compromised form. Mind_Swap_Epi5.mkv.mp4