User blog comment:D. Cello/Assassinews 10/05 -- Message Wall, Revelations trailer and release info... now with summaries!/@comment-78.149.241.135-20111006190546/@comment-4268634-20111006192949

The second hidden blade is concealed beneath the hook blade...or emerges from it. Not sure from the picture. But Ezio certainly can't put the second blade on his ass and fight that way can he?