The city of Hill Valley's clock tower plays a central role in the movie Back to the Future when it is struck by lightning, providing "Doc" Brown with the energy he needs to return to 1985. This Back to the Future t shirt plays off of that plot twist with its saying, which is also a reference to a World War II poster series. The Back to the Future Keep Calm Save T Shirt Sheer is heathered blue and features a soft feel and a tailored fit. An image of the clock tower discharging lightning bolts exactly at 10:04 p.m. is above the words "Keep Calm and Save the Clock Tower," a play on the British morale builder "Keep Calm and Carry On." Go back to a classic movie when you wear this Back to the Future t shirt!