un‧rav‧el past tense and past participle unravelled, present participle unravelling British English, past tense and past participle unraveled, present participle unraveling American English
to understand or explain something that is mysterious or complicated:
Detectives are still trying to unravel the mystery surrounding his death.
2 [intransitive and transitive]
if you unravel threads, string etc, or if they unravel, they stop being twisted together
if a system, plan, organization etc unravels, it starts to fail:
The company started to unravel when two of the directors were arrested.