The Client is a middle-aged man with blue eyes, pale skin, and dark brown hair as well as a beard. Throughout the show, he can be seen wearing a suit with a black tie, often decked up as a businessman. Whenever spoken to on the phone, people can hear his voice distorted as he masks his real identity. He is also the husband of Suzanne McGill.
The Client is often mean and ruthless and doesn't care about anyone. He is shown to be a genius, an evil mastermind who manipulates people into doing his doing. This is cleverly shown with Jason Osmond in seasons 3 and 4 of Greenhouse Academy and Judy Hayward in Season 2. However, he shows softness and kindness to his wife, Suzanne McGill who is also just as clever as he is.
In Your New Best Friend, The Client makes his first appearance. In this episode, he meets Jason Osmond at the Cave. He then brings an entire team of people to the Cave which leaves Jason confused. The Client then tells him that he was getting all of the magnetite out of the cave and replacing them with fakes. This leaves Jason confused which then prompts The Client to tell him about his plan to create a virus from the magnetite. The Client then takes Jason and brings him to his apartment. In Old Trophies, The Client asks Jason why he was looking at the surveillance camera at the Greenhouse. He then notices that there was still one piece of magnetite in the Greenhouse. Aggravated, he tries to think about how to get it out of the Greenhouse. In A Piece of Moon Rock, he realizes that the kids put a fake after Enzo had taken it. He then thinks of a plan to get it out. In The Hidden Flag, he calls up Enzo and tells him to hand over the magnetite. At first, Enzo doesn't do as he says but after he delievers some money, he does it. The Client tells Enzo to drop the magnetite off and resign from the Greenhouse. He does so, only for Suzanne to come pick it up. She then gets into the car with The Client and tells him "I've missed you, baby". They then kiss each other while he tells her, "Just a little bit longer". At the apartment, he starts putting a beeping noise inside the cave so that his plan could start. In The Beeps, Jason watches as Hayley and Leo go into the cave. He then tells The Client that they were just kids to which The Client replies "This is sweet revenge for you, buddy".
In The Quick One, Suzanne texts The Client about Hayley and Leo. At his apartment, the Client tells Jason that Hayley is alive, which Jason is glad to hear. He asks about Leo. "I don't know." says the Client carelessly. "Died, I guess?" Jason looks sad. "What's wrong?" the Client asks him. Jason recalls the Client telling him that they could do this without hurting innocent people. The Client responds by asking if they forced Leo into the cave. "Maybe this will cheer you up." suggests the client. He shows Jason three vials of the virus extracted from the magnetite. The Client explains to Jason that he will use it at Louis's tech conference. He then tells him, "Where else would you find 10 billionaires underneath one roof?" In A Not Totally Bad Person, Enzo tells The Client that he was on tv. The Client then tells him that he will deal with that and tells him to do a few things. Firstly, call Sophie asking for help. Second, tell her the address of the hovel that he meets up with the Russians. Third, The Client would place the virus under the table and the police would then arrest the Russians. In Gummy Bears, Suzanne tells him that there was a problem to which he tells her to fix it. He then knocks the game pieces of his board. In Cortinarius Orellanus, The Client's plan starts to work again. At his apartment, he discusses with Jason about what he will do next with Hayley and Leo. He then tells him that he would poison the children using a rare poison extracted from German mushrooms. In The Client (Season 4), he gets ready with Jason to attack everyone at the conference. He then arrives at the conference with Jason and threatens everyone. However, the kids foil his plan. Jason then gets taken to the hospital. After Brooke leaves, Jason begins mumbling to himself. It is then revealed that The Client was Jason all along.