Coulson and his team find themselves without anyone they can trust, only to discover that they are trapped with a traitor in their midst.
John Garrett's jet is attacked by S.H.I.E.L.D. drones after the Bus was hijacked; after escaping the drones with the aid of Coulson's Team, he docks with the Bus and joins the team. At the Hub, Jemma Simmons and Antoine Triplett begin working together to secretly upload Simmons's research on Skye's blood, only for a HYDRA assault on all S.H.I.E.L.D. facilities to begin, forcing them into hiding.
Phil Coulson locks Melinda May up in the interrogation room with Grant Ward, still believing she is the traitor. Skye discovers a secret code in a signal on S.H.I.E.L.D.'s network that she deciphers to reveal HYDRA's infiltration.
When the Bus arrives at the Hub, the group split into teams to capture Victoria Hand, who they believe to be the Clairvoyant, and save Simmons. Simmons and Triplett are captured by Hand, but she reveals that she was not actually part of HYDRA but believed that Coulson was, and recruited the two to aid her in stopping HYDRA.
Coulson, May, Garrett, and Leo Fitz manage to capture a computer room in the Hub, but while talking with Coulson, Garrett begins urging him to kill Hand without a trial, and accidentally reveals information about Raina that Coulson never disclosed to anyone, unwittingly outing himself as the true Clairvoyant.
In the ensuing battle, Coulson and May manage to kill the HYDRA agents and capture Garrett. The Hub is retaken and Captain America defeats HYDRA's trio of armed Helicarriers, but Nick Fury is presumed dead in the aftermath and the remaining S.H.I.E.L.D. agents are forced to go on the run.
Ward volunteers to accompany Hand to the Fridge so he can see to Garrett's imprisonment personally. In transit, Hand offers Ward the chance to execute Garrett to atone for killing Thomas Nash by mistake. He at first appears to accept the offer, but then instead guns down Hand, Jacobson and Chaimson, freeing Garrett and revealing himself as a HYDRA agent.
- Clark Gregg as Agent Phil Coulson
- Ming-Na Wen as Agent Melinda May
- Brett Dalton as Agent Grant Ward
- Chloe Bennet as Agent Skye
- Iain De Caestecker as Agent Leo Fitz
- Elizabeth Henstridge as Agent Jemma Simmons
- Bill Paxton as Agent John Garrett
- Saffron Burrows as Agent Victoria Hand
- B.J. Britt as Agent Antoine Triplett
- Christine Adams as Agent Anne Weaver
- Dayo Ade as Agent Barbour
- James Macdonald as Agent Jacobson
- Charles Halford as Agent Shaw
- Braden Moran as Agent Jones
- Cameron Diskin as Agent Baylin
- Kylie Furneaux as Agent Shade (uncredited)
- Alex Daniels as Agent Chaimson (uncredited)
- Zac Henry as TAC Team Agent #1 (uncredited)
- The Hub
- S.H.I.E.L.D. Academy
- The Triskelion (mentioned)
- S.H.I.E.L.D. East African Headquarters (mentioned)
- The Treehouse (mentioned)
- The Fridge (mentioned)
- Lisbon, Portugal (mentioned)
- Bahrain (mentioned)
- Dublin, Ireland (mentioned)
- World War II (mentioned)
- HYDRA Uprising
- Overkill Device
- Coulson's Team Hard Drive
- Pick-Lock Device
- Mouse Hole
- Bulletproof Vest
- GH.325 (mentioned)
- Peruvian 0-8-4 (mentioned)
- Berserker Staff (mentioned)
- Atmospheric Moisture Freezing Device (mentioned)
- Gravitonium (mentioned)
- Backscatter X-Ray Eye Implant (mentioned)
- Theta Brain-Wave Frequency Machine (mentioned)
- Flare gun (mentioned)
- S.H.I.E.L.D. SUV
- S.H.I.E.L.D. Jump Jet
- S.H.I.E.L.D. UAV
- Helicarrier (mentioned and footage)
- Project T.A.H.I.T.I.
- Nick Fury
- Felix Blake
- Thomas Nash
- Franklin Hall
- Akela Amador
- Dan Monroe
- Ian Quinn
- Jasper Sitwell
- Captain America
- Joanie Loves Chachi
- This episode is a direct tie-in with Captain America: The Winter Soldier.
- This is the first episode to end with the HYDRA insignia rather than S.H.I.E.L.D.'s.
|(Don't Fear) The Reaper||Blue Öyster Cult|