。
Please tell me in detail.
Literal
In-detail teach-[please-てください].
A polite request for full information. 詳らかに ('in detail, thoroughly') is a formal/literary adverb, more refined than the colloquial 詳しく. Formed from the na-adjective 詳らか (つまびらか, 'detailed, thorough') + に. The adverb carries a slightly literary, refined flavor — not something you'd use in casual speech.