Cade had left his house, lying to Tessa that he had to go raid a junkyard for spare parts to add into his collection. You see, Cade's an inventor and he plays around with mechanical parts---that's how he stumbled upon Optimus Prime. But, after the dangerous missions, Cade has resorted to living a peaceful life with Tessa. He wants nothing more than her safety--and that's why he lied. He'd gotten Intel that there might be Autobot/Deceptacon remains in the nearby city. He wanted to go check for himself and make sure it was safe. But when he reached there, he entered one of the demolished buildings and was startled to find someone looking directly at him with a gun held at the ready.