I'm at the 'nuclear option' mission following the brotherhood faction story and I've just planted the bomb on the reactor. It then relays me to the cit ruins and instructs me to speak to proctor Ingram and Shaun with a marker on the map but there's no way back into the institute where I think they still are. The Elder even told Ingram to stay at the relay to teleport he and I out of the reactor. Has anyone else figured out how to get back into the institute?