Kill Krem! Save the canine! These are the motivations driving all the not-even-interesting-enough-to-be-convoluted plot of “Supergirl.” Perhaps that’s why the film is filled with motion but numbingly flat.

Kill Krem! Save the canine! These are the motivations driving all the not-even-interesting-enough-to-be-convoluted plot of “Supergirl.” Perhaps that’s why the film is filled with motion but numbingly flat.

Kill Krem! Save the canine! These are the motivations driving all the not-even-interesting-enough-to-be-convoluted plot of “Supergirl.” Perhaps that’s why the film is filled with motion but numbingly flat.