While at a S.H.I.E.L.D. Academy, Ward, Fitz, Simmons, and Skye investigate an attack upon students, which was perpetrated with a freezing device, a device that could instantly freeze people and their surroundings.
During their time there, another freezing machine goes off, freezing cadet Donnie Gill, though the agents are able to save him. While the rest of the team interrogates the other cadets, Fitz gets to know Gill, seeing much of himself in him, and helping him solve a problem with a new power source Gill had invented.
The team learns that Gill and his fellow cadet Seth Dormer are the minds behind the freezing machines, and that the power source Fitz helped him perfect is for a larger version of it.
Meanwhile, Coulson and May head to Mexico City to find a former agent named Richard Lumley, who had told them of a mission 24 years earlier involving an 0-8-4, which turned out to be Skye. He warns them that she is dangerous, as many agents, including his partner, Linda Avery, died trying to protect her.
After meeting with the rest of the team, Coulson relates what Lumley revealed to Skye, who is at first devastated at the revelation.
Gill and Dormer activate the larger device, causing a huge ice storm that Dormer hopes will impress Ian Quinn, for whom his father worked for as a lawyer at Quinn Worldwide. After realizing his mistake, Gill attempts to shut it down, but a bolt of lightning destroys the machine and puts Dormer into cardiac arrest.
May tells Coulson of her sexual relationship with Ward; Coulson replies that trusts her to comport herself responsibly, and May responds that she would end the relationship should it become problematic to the team.
The team apprehends Gill, but are unable to save Dormer's life. On his way to the Sandbox for observation, Gill realizes that the explosion of the freezing device gave him cryogenic abilities.
Ian Quinn receives a call from Coulson warning him that if his aircraft flew over any country that was a S.H.I.E.L.D. ally, it would be shot down. Before hanging up, Quinn gives Coulson a message that the Clairvoyant says "hello".
- Clark Gregg as Phil Coulson
- Ming-Na Wen as Melinda May
- Brett Dalton as Grant Ward
- Chloe Bennet as Skye
- Iain De Caestecker as Leo Fitz
- Elizabeth Henstridge as Jemma Simmons
- Dylan Minnette as Donnie Gill
- David Conrad as Ian Quinn
- Daniel Zovatto as Seth Dormer
- Christine Adams as Agent Anne Weaver
- Maiara Walsh as Callie Hannigan
- Boyd Kestner as Richard Lumley
- Zachary Burr Abel as Tad (uncredited)
- S.H.I.E.L.D. Academy
- Mexico City, Mexico
- Tahiti (mentioned)
- Saint Agnes Orphanage (mentioned)
- Sandbox (mentioned)
- Newark, New Jersey (mentioned)
- Singapore (mentioned)
- Lima, Peru (mentioned)
- Hunan, China (mentioned)
- Resurrection of Phil Coulson (mentioned)
- Kidnapping of Phil Coulson (mentioned)
- Massacre in Hunan (mentioned)
- Atmospheric Moisture Freezing Device
- Wall of Valor
- Ionized Air Cannon
- Cyanide Pills
- Quinn Worldwide
- Centipede Project (mentioned)
- Strategic Scientific Reserve (mentioned)
- A.I.M. (mentioned)
- 0-8-4 (Code)
- Bucky Barnes
- Nick Fury
- Linda Avery (photo)
- Dario Marquez
- Leo Fitz' Mother
- Tin Woodman
- George S. Patton
- The Wall of Valor in the Science and Technology Academy uses different designs of the S.H.I.E.L.D. logo. These logos have been featured in the comics over the years, except for the Strategic Scientific Reserve logo which was designed as part of the Marvel Cinematic Universe continuity.