The new 30 for 30 documentary Be Water opens up with a black-and-white screen test of its subject, martial arts legend Bruce Lee, from the mid-Sixties. Lee silently follows instructions to turn his head to different angles, before the off-screen director says, “Now the camera will pull back,” and invites his subject to demonstrate some kung-fu moves with a member of the crew as his theoretical target. Lee is utterly relaxed, putting his audience at ease with a joke about how accidents can happen even in an exhibition like this. He casually shifts into his stance, and suddenly his right arm is exploding towards his fake sparring partner with speed that seems superhuman. He does it several times, just as insanely fast, before the director asks him to pause and reposition himself so the camera can better capture his incredible moves.