The clip shows Skye (Chloe Bennet) in a ferocious fight with SHIELD-agent-turned-Hydra-operative - Agent 33 (disguised as Melinda May - played by Ming-Na Wen).
The episode is titled '...Ye Who Enter Here', and it airs on Tuesday, December 2, 9 pm.
Marvel also released the official synopsis of Agents of SHIELD Episode 209, which you can check out below -
“…Ye Who Enter Here” – SHIELD discovers the ancient city before Hydra, but uncovering the secrets may require one of Coulson’s team to make the ultimate sacrifice. Meanwhile, May and Skye race to get to Raina before Whitehall takes her, on TUESDAY, DECEMBER 2 (9:00-10:00 p.m., ET) on the ABC Television
“Marvel’s Agents of S.H.I.E.L.D.” stars Clark Gregg as Agent Phil Coulson, Ming-Na Wen as Agent Melinda May, Brett Dalton as Grant Ward, Chloe Bennet as Skye, Iain De Caestecker as Agent Leo Fitz, Elizabeth Henstridge as Agent Jemma Simmons and Nick Blood as Lance Hunter.
Guest starring are B.J. Britt as Triplett, Adrianne Palicki as Bobbi Morse, Henry Simmons as Alphonso “Mack” Mackenzie, Ruth Negga as Raina, Patton Oswalt as Sam/Billy Koenig, Reed Diamond as Daniel Whitehall, Jeffrey Corbett as Chad, and Brittnee Garza as Cashier.
”…Ye Who Enter Here” was written by Paul Zbyszewski and directed by Billy Gierhart.
Thanks to comicbook.com