: The largest e-book platform in Russia typically offers the House of Night series in multiple formats, including FB2.

While some international sites primarily offer EPUB or Kindle formats, many Russian-language platforms provide FB2 versions for purchase:

: Offers English versions in EPUB and other formats .

A House of Night Book 7-12 by: P.C. Cast & Kristin Cast ... - VK

If you are looking to download it in format (a common format for Russian e-readers), Official E-Book Retailers

: Provides the e-book in EPUB format , which can be converted to FB2 using free tools like Calibre . Libraries and Free Alternatives

The book you are looking for is (Russian title: "Разоблаченная" ), which is the 11th installment in the popular House of Night series by P.C. Cast and Kristin Cast.