In the “Trust But Verify” episode of Arrow, three armed men have been robbing armored trucks. Oliver Queen suspects the ringleader of the robbers is a former soldier named Ted Gaynor, who is on his list. There’s only one big problem. Ted Gaynor used to be Diggle’s commanding offer in Afghanistan, and Diggle thinks there’s no way the man that saved his life could be guilty.
Oliver goes to pay a visit to Ted Gaynor as Arrow, but Diggle shows up and foils Arrow’s plans. After protecting Ted from Arrow, Diggle is given a job with Ted’s security company, which is called Blackhawk Squad Protection Group.
Meawhile, Malcolm Merlyn appears to be meddling in everyone’s life. Moria and Thea Queen are having a mother and daughter day, when Moira gets a call from Malcom, which makes Thea suspicious that her mom has been having an affair. Malcolm also calls his son Tommy and arranges to have dinner with Tommy and Laurel.
Thea tells Oliver that she thinks their mom is having an affair, and Oliver confronts Moira. However, Moria tells Oliver it was his father Robert who was unfaithful, and she just sometimes meets with Malcolm for company advice. When Tommy and Laurel have dinner with Malcolm, Tommy realizes the only thing his dad wanted was to get his signature on a form that would shut down his dead mother’s free clinic.
Oliver Queen enlists Felicity to hack into some of Blachawk’s files, and she finds out someone at that company has been planning the armored car robberies. Oliver gets the file and as Arrow stops and injures one of the robbers, but the robbers still manage to get away. Diggle believes it’s another Blackhawk employee named Knox, who is behind the robberies. While investigating the van used in the robbery, Diggle is confronted by Knox, but he is surprised to learn Ted is involved as well. In fact, Ted has kidnapped Diggle’s sister-in-law to force Diggle to help them in one last armored car robbery.
However, when Diggle sees his opportunity he turns on Ted, so that his sister-in-law can get away. Ted is about to shoot Diggle, but luckily Oliver has been listening in on a tracking device he planed on Diggle. Arrow kills Ted to keep Ted from killing Diggle.
Meanwhile, Thea has walked in on her mother and Malcom together, and she is still convinced they are having an affair. Thea takes a party drug called Vertigo, and she drives off and crashes her car. Thea survives the accident, but a toxicology test at the hospital shows the drug in her system, and she is arrested.
Oliver and Diggle also have a conversation about trust, and Oliver reveals it’s difficult for him to trust after what happened to him on the island. In flashbacks, it’s revealed that Oliver infiltrated a group of masked men on the island to try to rescue his friend and mentor Yao Fei. However, in a big twist, it turns out that Yao Fei was actually one of the masked men.