Luc Besson's Lucy continues a happy trend this summer. Rather than brain-dead battle movies (like Transformers: Age of Extinction), many sci-fi movies have achieved a balanced combination of thoughtful or clever ideas and exhilarating action, one feeding into the other. Thus Lucy follows nicely in the footsteps of Edge of Tomorrow, X-Men: Days of Future Past, Snowpiercer, and Dawn of the Planet of the Apes. Scarlett Johansson stars as the title character, an ordinary girl living in Taipei whose shady boyfriend ropes her into delivering a suitcase to a powerful gang lord, Mr. Jung (Choi Min-sik, from the original Oldboy). She is overpowered and then used as a drug mule to transport an experimental new substance called CPH4 in her intestines.