Mysterious texts involved in shutdown (10)

I believe the answer is:
whodunnits
'mysterious texts' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'involved in shutdown' is the wordplay.
'involved' indicates anagramming the letters (involved can mean confusing or complex).
'in'+'shutdown'='inshutdown'
'inshutdown' is an anagram of 'WHODUNNITS'.
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