The underground passage is a room on the Island.
The passage toward the far end left appears to be leading to the road to annex while to the right will lead to a underground private room. Few cages can be seen inside a small room, where as dog food are presents.
In this room, Leon and Ashley encounter two regenerador, one is at the front and the other at the back, the can be either fought or be avoided. At the end of the room, there is an electronic switch which required Leon and Ashley to pull at the same time.
|The closed shutter||CHECK||Doesn't look like I could lift this up with my bare hands. There's gotta be a switch for this shutter somewhere.|
|The switch near the shutter||CHECK||This lever's not working.|
|The red switch||CHECK||The auxiliary power has been activated. (view shutter opening half way) The shutter's stuck.|
|The shutter while it is half opened||CHECK||There's just enough space for Ashley to crawl under.|
|The lever behind shutter||CHECK||This one's not working either.|
|The door to the road to the annex while it is locked||OPEN||(locked door sound) It's locked. It looks like this door's got a high security lock.|
|The levers next to the locked door||CHECK||There are levers on both sides of the door.|
|The levers while Leon and Ashley stand by both||CHECK||Let's give it a try.|
- Koichi Hamamura, ed (2006) (in Japanese). biohazard4 kaitaishinsho revised edition. Famitsu. ISBN 4-7577-2638-4.