Celebrity Hijack: It's The Office's Gareth (VIDEO)

It was the revenge of the nerd in the Big Brother: Celebrity Hijack house when The Office star Mackenzie Crook took control. When Monday's Hijacker, best known as The Office's Gareth, addressed them just after noon, the housemates went wild. "This is the voice of Mackenzie Crook. Would housemates gather on the sofas immediately?" When they didn't move fast enough, he responded: "Just remember, it's your own time you're wasting." Once they gathered, he began: "Today is Nerd Day. And I would like you to become nerds for the day. I will be your mentor of the mundane, your geeky guru." "The storeroom is now open for you to collect your nerd costumes." VIDEO: Watch a clip of Mackenzie Crook introducing himself to the housemates

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