Code for captions in gallery thumbnails

Hi all,

A site I am working on uses a theme (Keres), in which the gallery templates don’t allow for showing captions on gallery thumbnails. Customer support for the theme just told me it needs to be custom coded, but wouldn’t help beyond that.

Can anyone help with the code (or any other way) to show captions on a gallery thumbnail page, if it’s not already part of the theme?

Thanks!