TV Guide has some details about the episode with mention S.H.I.E.L.D. gets attacked by the Asgardian Lorelie (Elena Satine) with Sif coming to make the save.
Jaimie Alexander will appear on the Marvel's Agents of S.H.I.E.L.D. episode "Yes, Men" on March 11th.
"We always have our radar up for ways to tie our series into the Marvel films and bringing in an Asgardian really cements that connection," said executive producer Jed Whedon. "Lady Sif comes here on a hunting mission — sent by Odin — to find her arch-enemy Lorelei and bring her back to Asgard. It throws our agents for a loop when they find themselves in a fight right alongside this powerful woman from Thor's world."
Marvel's Agents of S.H.I.E.L.D. airs Tuesdays at 8pm ET on ABC.