Here is the quote from series "Sherlock" s04e01:
— You say he filmed that video message before he died?
— You also say you know what he's going to do next. What does that mean?
— Perhaps that's all there is to it. Perhaps he was just trying to frighten you.
Does that generally mean "that's all/that's finished"?
If yes, then what is the purpose of the second part of this sentence ("there is to it")?
And maybe I misunderstand it completely. The subtitles didn't contain any punctuation marks, that's also confusing. Could you explain this phrase in pieces, please?