Never use an adverb to modify the verb 'said' . . . he admonished gravely. To use an adverb this way (or almost any way) is a mortal sin. The writer is now exposing himself in earnest, using a word that distracts and can interrupt the rhythm of the exchange.
Elmore LeonardA friend of mine who is in the publishing business knew I was writing a book, and he said, 'Have you said anything yet about the good guy? Because I know you spend so much time with the bad guys.' Because they're fun. So then you have to make the good guy fun, in order to compete. That's the challenge.
Elmore Leonard