Verb (used with object) : to unravel a situation; to unravel a mystery.    From Dictionary.com. 

He was a negotiator and an unraveler of knots, and there were still people who suspected, because of his wartime activities, that he had a cloak and a dagger somewhere concealed.    From Wordnik.com.  [Cargo of Eagles]

He was tossing out Greek declensions to the prof. like a geyser, and Conny Matthews, our champion Livy unraveler, had shown him how to hold a Latin verb in his teeth while he broke open the rest of the sentence.    From Wordnik.com.  [At Good Old Siwash] Reference

Rutilius Rufus listened with interest, and when the moment came, offered his answer; what he didn’t tell his sister and brother-in-law was that the real unraveler of the conundrum was Gaius Marius, whose terse letter he had just received from Africa.    From Wordnik.com.  [The First Man in Rome]