Slick
tech -
wonder Iron Man (Robert Downey Jr), buff
boy - scout Captain America (Chris Evans) and bipolar scientist Bruce Banner (Mark Ruffalo) all take convincing, and Whedon's script zings with crisp banter and propulsive action as the team — eventually abetted by Loki's conflicted brother, Thor (Chris Hemsworth)-- wrinkle out their differences and needle each others tender spots, both literal and figurative.