The water is rushing in far faster than you could have expected thanks to Lamb, and the whole of Siren Alley is going to be rattled loose—you have to get out of there! Retrace your steps back through the Pump Station Access area to the room with the massive pumps. The previously short-circuited door on the right is now open. Go through this door to Hedone Plaza and climb the stairs to the Maintenance Area. Have the Shotgun or Speargun on hand in case any Splicers try to kiss you goodbye.
Make the journey back through the newly flooded Little Eden Plaza and exit back out onto the seafloor, just as you entered several hours earlier. Proceed north up the sloping ocean floor to the airlock leading into Dionysus Park.
