both the video and the subtitle file in the same folder.
OpenSubtitles: Look for the "JYK" tag in the subtitle name to ensure the timing matches your video file exactly. subtitle Leviathan.2014.1080p.BRRip.x264.AC3-JY...
To find and use the correct subtitle for this specific release, you can look for .srt files on popular subtitle databases. Subtitle Search Engines both the video and the subtitle file in the same folder