The Patriot is the tenth episode of the fourth season of the television series Agents of S.H.I.E.L.D. and the seventy-sixth episode overall.
Separated from their team, Agents Coulson and Mackenzie discover a shocking secret about Mace, leaving all of S.H.I.E.L.D. in a precarious position.
A ceremony is held in Sunbury, Pennsylvania to officially announce that Quake is a full member of S.H.I.E.L.D. who fought the Watchdogs under S.H.I.E.L.D. supervision all along. While Michelle Caldwell delivers a speech about how Quake saved her, Phil Coulson notices that a S.H.I.E.L.D. agent supposed to ensure the security of the ceremony is missing. Shortly after, a sniper attempts to assassinate Director Jeffrey Mace. Coulson and Alphonso Mackenzie take Mace and Burrows, who carry a mysterious suitcase, to a Quinjet in order to evacuate them to safety while Quake disposes of the terrorists and arrests one of them, Yuri Zaikin. Glenn Talbot, who was present at the ceremony, returns to the Playground, where he informs Melinda May's LMD and Jemma Simmons of the attack. The General orders May to interrogate Zaikin and Simmons to check whether Burrows is with Mace.
Meanwhile, at the Radcliffe Residence, Leo Fitz and Holden Radcliffe discuss the attack as well and Fitz tells Radcliffe that he should not come to work with S.H.I.E.L.D. for a few time before leaving. After Fitz's departure, Radcliffe and Aida discuss their plan of replacing Melinda May by a Life-Model Decoy who is unaware of her true nature and of her mission of finding the Darkhold. Radcliffe also worries about the fact that they cannot seem to stabilize May's condition so that she remains calm and sedated, believing to be in a relaxing simulation. May finally wakes up and tries to escape before being stopped by Aida, who sedates her once again.
May and Quake interrogate Zaikin, who reveals that he was not the only terrorist sent to kill Mace. Indeed, the Director's Quinjet is attacked and Burrows falls to his death before the plane crashes, killing agent McCafferty who was flying it. Coulson, Mackenzie and Mace are unharmed and realize that the Quinjet's systems were hacked. Figuring out that they are in danger, they decide to leave, but Mace decides that they must first find Burrows's body. At the Playground, Talbot and the others cannot locate the missing S.H.I.E.L.D. agents. After Quake, Simmons and May leave Mace's office, Talbot reports the investigation to the President, telling him that they do not know whether the "package" is safe. Fitz returns to the Playground and has a short argument with his girlfriend about his involvement in Aida's design before helping her to locate their friends.
Talbot carries on Zaikin's interrogation but cannot get any information from him. He complains about it to Fitz and Simmons. Shortly after, Simmons discovers that she has access to something called Project Patriot and she and Fitz ask Talbot about the suitcase Burrows used to carry around the Director. Meanwhile, Coulson, Mace and Mackenzie discover that the terrorists are using HYDRA equipment but Mace insists on finding Burrows's corpse, but the terrorists already reclaimed it, as well as the suitcase. Coulson and Mackenzie attack the terrorist but are surprised to see that Mace just seizes the suitcase and flees without fighting. He is found by a terrorist who shoots him in the leg before being killed by Coulson and Mackenzie, who do not understand why Mace did not use his powers to defeat his opponent. The reason is simple, and Simmons and Fitz learn it from Talbot: contrary to what was publicly announced, Mace is not an Inhuman. Instead, he gained his super strength by injecting himself a serum inspired from Calvin Zabo's Formula that Burrows carried in the suitcase.
Coulson and Mackenzie take Mace to the terrorists' stash to attend to his wound, but are soon confronted with another group of enemies. At the Playground, Simmons suggests to use Aida's severed head in order intimidate Zaikin. The process proves to be successful and Zaikin admits that he works for the Watchdogs and gives them the location of the crashing site. This enables May's LMD to go on the field in order to rescue Coulson, Mackenzie and Mace, and together they manage to take down all the terrorists before returning to the Playground. However, May's LMD was hurt in the fight, which makes her realize that she is an android. Meanwhile, Fitz downloads the data of Aida's head on his phone to keep working on it. In Mace's office, Mace agrees to remain the official Director of S.H.I.E.L.D. while Coulson takes the leadership about field actions, becoming de facto Director.