Fail-Safe Switch
When activated, a TARDIS will seek out and lock on to the nearest habitable environment. This step will be omitted if the TARDIS is already materialized in such a location. Once locked on, Failsafe prevents any dematerialization or materialization of a TARDIS until the switch is deactivated. Emergency doors will be generated in any areas of the TARDIS that (due to dimensional instabilities) have been cut off from the Main Doors in the Control Room. These doors will lead to the outside of a TARDIS and will appear integrated into the local environment. The existence of these doors will be unstable until the emergency bypass device is engaged.