Mater's Spy Surprise is the third and so far final episode of LEGO Cars 2: Mater's Brick Tales.
Mater was driving near the mountains of Radiator Springs. He said that today was an ordinary day. Then, he saw Acer, who he didn't know was Acer, because Acer was disguised as a granny. Mater noticed that Acer had lost a wheel, so he decided to help him.
Grem was hiding behind Mater. When Mater was about to help Acer, Grem pushed Mater off the cliff. Acer put his tire back on himself and high-fived Grem. However, Mater used his rockets to stop him from crashing into the ground. Mater was having so much fun flying and even called himself an airplane.
When Grem and Acer saw him, they each shot a missile at him. Mater, being chased by the missiles, realized that flying wasn't as easy as it looks. He was having trouble controlling the rockets and changes his mind about being an airplane. While still unable to control his rockets, he caused the missiles to blow up Grem and Acer.
After Mater landed, he couldn't believe that he did everything that happened.