"What is this thing?"
This disambiguation page lists articles associated with the same title. If a link led you here, you may wish to change that link to point directly to the intended article.
Red Door, or Red Hatch, may refer to the following:
Red Hatch, which can be opened with Missiles
Red Hatch, which can be opened with BSL Security Level 4
Red Door, which can be opened with the Plasma Beam
Red Blast Shield, which can be opened with the Imperialist