This article raises the problems of the reception of books that, from a Catholic perspective, were considered heretical or problematic, from the privileged perspective of the Earl of Condomar, the ambassador of Philip III of Spain to the court of James I of England. In addition to the earl’s political interest, as well as his status as a bibliophile and the owner of a notable private library, a number of contemporary documentary elements are also important for this analysis: namely, the catalogue of his library (1623) in which the count’s librarian creates a “hell”, the post mortem visit of the inquisitors (1626), and the correspondence that amplifies and details the conflict of the circulation of these books.