Dic: unravel (its three meanings as a verb) and ravel

• His government began to unravel because of a banking scandal. (1)
• He was good with his hands and could unravel a knot or untangle yarn that others wouldn't even attempt. (2)
• The stairway carpet is so frayed it threatens to unravel. (2)
• A young mother has flown to Iceland to unravel the mystery of her husband's disappearance. (3)
• Gradually, with an intelligent use of flashbacks, Yves' story unravels. (3)

unravel:

1. VERB △If something such as a plan or system unravels, it breaks up or begins to fail.
2. VERB △If you unravel something that is knotted, woven, or knitted, or if it unravels, it becomes one straight piece again or separates into its different threads.
3. VERB △If you unravel a mystery or puzzle, or if it unravels, it gradually becomes clearer and you can work out the answer to it.

Cf. ravel: verb.

1. to tangle or become entangled.
2. (of a fabric) to fray out in loose ends; unravel [Middle Dutch ravelen]

..... Cobuild, Collins Essential