And the cross-promotion and cross-pollination keep on coming: Tonight’s episode features guest star Jaimie Alexander, reprising her Marvel movie role as Sif, the Asgardian warrior introduced in 2011’s Thor. She also appeared as Sif in the 2013 movie Thor: The Dark World, and on TV in one of last year’s episodes of this series. And here she is again, in a plot that sets the stage for some of the events in the next Marvel movie to come down the pike, Avengers: Age of Ultron.