"It was very personal. It was the month after the accident happened with my brother Paul Walker and it was the first time I had worked since. Although it was challenging, just to get back to work was therapeutic - especially as Groot. There was an innocence about the character that was just refreshing." Vin Diesel tells The Hollywood Reporter that working on the set of Guardians of the Galaxy helped him recover from the death of his Fast & Furious co-star Paul Walker last year (Nov13).