The Meriwell is the spacecraft that Sirius Amory uses to reach the Keywork in The Afterman: Ascension. The ship was named after Sirius's wife, Meri Amory. The AI, All Mother, resides on the ship when Sirius is present.
This is name given to the lower deck of The Meriwell. Sirius travels through here in order to make contact with the Keywork. See The Hollow (song) for more information.
While removing the soul of Domino The Destitute from Sirius's body, a tone was transmitted by All Mother from Sirius' suit to the ship which caused it to explode.
After escaping the Keywork, All Mother tries to salvage pieces of the Meriwell in order to communicate with Heaven's Fence, but it fails.