Most EPUBs include the back-cover copy on one of the first few pages.
"Agua" is a common title for Spanish-language works. A notable recent "Agua" related book is Agua: A Novel by Begoña Oro, or various scientific papers on water management. Agua - Alex Roma.epub
Where you the file (e.g., a specific storefront or author site)? Any character names or specific themes you remember? Most EPUBs include the back-cover copy on one
The or general plot (e.g., sci-fi, romance, non-fiction)? Agua - Alex Roma.epub
Open the file in an e-reader (like Apple Books, Kindle, or Calibre) and view the "Book Info" or "Synopsis" section.