Fifteen years ago at the Juvenile Secure Unit in Plymouth, Massachusetts, a young Grant Ward was locked up for setting fire to his home. He had no idea his brother was inside at the time. John Garrett visits Ward with a onetime offer. It involves a secret organization looking to recruit people just like him. Garrett assures him that if he says yes that no one will ever mess with him again. Moments later, armed men storm the room. Garrett smiles assuring Ward that things are about to get fun.
A notorious drug lord with ties to HYDRA has been assassinated by Deathlok. The team ponders what this means as they deduce that Garrett has been developing Centipede serum and needs GH-325 to stabilize it. That's why Ward came back for the hard drive which has a Trojan horse. The virus still needs to be activated though. The team needs to break into a Cybertek office. They won't be acting as S.H.I.E.L.D. agents. They'll be more like vigilantes. There's no way Coulson is going to let Garrett and Ward get away with murder.
Triplett brings in his grandfather's spy technology. He has a suitcase filled with cool old gadgets. Coulson and May pitch some ideas to Cybertek officials. It's all part of a ruse to get inside the building. They neutralize a couple guards and sneak into a secure area. Using a few of those cool old gadgets, they find that all of HYDRA's files are hard copies. They uncover that John Garrett was the first Deathlok. Coulson and May toss the entire file cabinet out the window and zip-line to an escape.
The team realizes that Garrett wants GH-325 for himself as well as his army of super soldiers. The biomechanics in his body are fine, but his organs are failing. The Cybertek team gives him a month or two to live. Nevertheless, plans are moving forward in Cuba. Raina lets Ward know that she found files suggesting that Skye was a baby girl who may have had parents who were literally monsters.
The team heads into Cuba. Fitz and Simmons find the bus at an airfield. Garrett and his crew are looking to bug out. Fitz and Simmons are ordered to not engage. That's going to be tough once Ward finds their hiding spot. He brings them aboard the bus. Fitz uses an old gadget to fry some electrical devices inside. It also has an effect on Garrett, who has been having painful attacks more and more frequently. Fitz tries to convince Ward to let him die. He doesn't have to take orders from him anymore. Ward ignores his plea.
In the past, Garrett leaves Ward alone in the woods to survive on his own. Six months go by. Garrett returns to teach him some lessons in combat. He spills the details of how he became disloyal to S.H.I.E.L.D. and his allegiance to HYDRA. Garrett lets Ward know that he's been accepted as a S.H.I.E.L.D. agent. This is how it all began. In the present, Garrett orders Ward to put down their two prisoners. Fitz knows that Ward is a good person deep down. He tries to convince him of that. Ward admits that he does care about them. He sees this as a sign of weakness. That's why he jettisons Fitz and Simmons in a pod into the ocean below.
Garrett asks Raina to jump start his system. There's no guarantee the final ingredient will work. Garrett is jolted into a much more alive state. Elsewhere, Coulson and the rest of the team are trapped by centipede soldiers. There's no escape. In Washington, Ian Quinn meets with military big wigs with an offer to sell them a thousand super soldiers under the guise of providing the world security. He offers them a tour of their brand new Cybertek facility.