The Somnium Tenebris is a heavy dreadnaught, psionic-propelled ship. It requires protein to maintain vital systems.
— The Navigator

The Somnium Tenebris, also known as the Dark Dream, is the sailing vessel of the Chain of Acheron. With Slim as its pilot, the Chain uses the Somnium to cross the Sea of Stars and continue their journey to Capital.


The ship is a galleon-sized, massive living creature with all the amenities of a first-rate ship. It is directed by the Mindwitness, known as the navigator or Ship Intelligence. It is piloted via direct interface with the brain, and it requires the pilot to possess telepathy in order to access the direct interface.


Agents of Ajax[]

The Somnium Tenebris was a mind flayer vessel, crewed by enslaved Duergar and Githyanki. Though recently, a mutiny occurred. Mortum appeared to the slaves on the ship and offered them the power to overthrow their masters if they agreed to serve Ajax. Most of the slaves agreed and overthrew the mind flayers.

When first spotted on the Sea of Stars, the Somnium appears to operate as an agent of Ajax, bearing his livery upon their sails. According to Captain Massingham, this was a recent change.

The Somnium was controlled by the Githyanki and Duergar when the Chain boarded and captured the ship.  

The battle with the Rosso Cielo[]

The Somnium Tenebris, in service of Ajax, crossed paths with the Rosso Cielo while she transported the Chain from Blackbottom to Capital, after the events of the Battle of Blackbottom.

The ship attacked the Rosso Cielo with large tentacles, ensnaring it, and then boarded with Duergar. The Chain, along with the crew of the Rosso Cielo, defeated the boarding units and the senior officers ordered a boarding action of their own. The Chain was able to defeat the crew of the Somnium and claim it as their own.

Behind the Scenes[]

The ship is modelled after a Moon Class Mind Flayer Dreadnaught from the Spelljammer D&D setting. A floor plan of that ship can be found here.