"Castle" (tentative) is the term given to the first stage in the Resident Evil 4 (biohazard 4) development cycle, after an earlier and unrelated BIOHAZARD 4 evolved into Devil May Cry. This game was being developed by Production Studio 4 alongside Resident Evil and was announced in 2002 as part of the CAPCOM Five agreement. In the West it is otherwise known as the "Fog" or "Mist" version, and is recognized as such by developers.