"It is a desperate time for Hiigara. The Vaygr encroach from the Eastern Reaches. Their motives a mystery, they are brutal and unrelenting. Deep inside the Great Derelict at Tanis, construction of a new mothership is underway. With it, there stands a chance to defend what so many paid for with their lives." - Geoff Thomas, Assistant Producer

"At the very beginning of the game, you'll see the hyperspace core being inserted into the mothership; a series of tests has been planned before the enormous vessel will launch from the secret base where it was built. But after only a few minutes of basic tasks, an outlying ship detects something that will cut the tests short: the first wave of a Vaygr bomber attack." - Sam Parker, GameSpot

It would appear that the massive shipbuilding complex we have seen constructing the new mothership is actually part of an ancient relic, put to use by the Hiigarans as a secret base.

Tanis is located in the Great Wastelands.

In biblical history, Tanis was the home of the Well of the Souls, the last known resting place of the Ark of the Covenant. Homeworld is known for its biblical references (most notable among them Kadesh, the site where some of Moses' people abandoned him to settle). One can only guess at what metaphor is in use here.