“Lucy,” a sci-fi action thriller arriving in the heat of midsummer, is a high-velocity sprint to the finish. Lucy, an American student living in Taiwan, is a normal young woman one day, a superwoman ...

So let's start with the enticing premise of Luc Besson's "Lucy," starring Scarlett Johansson: Human beings only use 10 percent of their brain capacity. Imagine what it would be like if we could access ...