A team of Angels, led by senior operative John Bosley (Patrick Stewart) (Charlie's first and original assistant), capture international embezzler Jonny Smith (Chris Pang) in Rio De Janeiro and turn him over to American authorities. A year later, the European division of the Townsend Agency is informed that Elena Houghlin (Naomi Scott) (a scientist and creator of the Calisto project who later gets recruited to become an Angel), an engineer and programmer employed by entrepreneur Alexander Brock (Sam Claflin), wants to expose her superiors, namely Brock's head of development, Peter Fleming (Nat Faxon), for covering up a discovery about how an energy conservation device that she helped invent named Calisto has the potential to trigger fatal seizures when used. She meets with operative Edgar "Bosley" (Djimon Hounsou) to turn over her findings, but an assassin named Hodak (Jonathan Tucker) ambushes the meeting and subsequently kills Edgar and leaves Elena to drown.Edgar's protege, Jane Kano (Ella Balinska) (a former MI-6 agent who became an Angel), rescues her and brings her to operative Rebekah "Bosley" (Elizabeth Banks) (a former Angel who became one of Charlie's assistants) with the help of her partner, Sabina Wilson (Kristen Stewart) (a wild and rebellious Angel). Elena tells Rebekah that Calisto can be hacked and turned into an EMP on the human body, triggering seizures and deaths on a mass scale.Meanwhile, John, who has since retired from the agency, discovers that Rebekah has tagged him with the agency's specialized sub-dermal implant without his knowledge.Rebekah tasks Jane and Sabina, joined by Elena, with breaking into Brock's corporate headquarters to steal the remaining Calisto prototypes before they can be duplicated. Elena finds one of the devices but is forced to use it to escape, killing a security guard in the process, while the other prototypes are already gone, and Fleming is identified as the thief. Rebekah tracks him to Istanbul, where Jane utilizes one of her old intelligence contacts, Fatimah (Marie-Lou Sellem), to locate Fleming. They track him to a remote rock quarry, where the supposedly imprisoned Smith is revealed to be Fleming's intermediary for selling Calisto. Hodak is also present and kills Fleming before the Angels break up the sale. Rebekah suddenly disappears, allowing Smith and Hodak to escape with the prototypes.Returning to their safe-house, Sabina shares her growing belief that Rebekah is secretly working against the agency and has been manipulating them to steal Calisto for her own benefit. While the three ponder Sabina's suspicion, safe-house is bombed. Rebekah shows up only to be shot by John, who has come to rescue Elena. Jane and Sabina manage to survive and seek medical help from Fatimah.Rebekah reappears and explains that John is the real traitor and that he has spent the last few decades secretly building his own network within the agency after he was passed over to succeed the late Charlie Townsend.John takes Elena to a party hosted by Brock, who reveals himself as the mastermind behind the attempt to assassinate Elena and, unbeknownst to him, John's plan to turn Calisto into a weapon. Using Elena's colleague Langston (Noah Centineo) as a hostage, John forces her to program a Calisto device to kill both Langston and her before leaving. The Angels, having deduced his plan due to the information provided by Smith, who is later revealed to have defected to their side, show up and rescue Elena and Langston, Elena having already disabled the Calisto device.Jane exacts revenge by impaling Hodak on a spike, while Rebekah catches up with John and his men. Outnumbered, she has other Angels posing as guests subdue the men, after which Sabina knocks out John with a punch. Brock is arrested for conspiracy, and Jane and Langston start a relationship. Elena is recruited as an Angel by the Townsend Agency after passing a series of rigorous training exercises and receives an official Angels tattoo.