The opening scene of “Finch” is spectacular, Tom Hanks in a cumbersome protective suit prospecting in the wreckage of our planet after a “solar flare” has destroyed most it. The visual depiction of this radioactive, ozone-holed world aroused all my Anthropocene Age fears. And the rest of the first half of this ambitious-yet-modest film works brilliantly. We see that the survivor, an ex-IT superstar, has a cute dog he loves, and we watch him create a clunky-looking robot who instantly appeals. As the trio flees west across America’s vast wasteland in a specially rigged van, aiming for the San Francisco Bridge, all seemed in hand for an intriguing, intelligent hour and a half. Hanks is in top form, the human-robot dialogue avoids pitfalls, spectacular scene follows spectacular scene, and a sense of foreboding builds. Unfortunately, the second half of Finch slides into mawkishness and slumping tension. By the end, I was fidgeting with embarrassment. So, by all means while away time with this interesting dystopian aside, just don’t expect The Road.