Spoilers, of course.
So I heard on Radio Free Skaro that who I took for a beardless dwarf in the trailer is meant to be Fenric, as played by Mark Gatiss. Of course if you say Fenric a classic Doctor Who fan responds, “Curse of…” and there probably is a connection, given that the trailer contains a neon sign for “live chess”. However, that makes their chumminess in the trailer more than a bit confusing.
But Fenric does come from Norse mythology, being better known as Fenrir. If the next episode explores that connection, could the ever-so-popular metal eyepatches have something to do with Odin? Could they maybe give you omniscience or something? Hmmm.