Rachel, during his speechlessness, looked at him unbelievingly.
Unbelievingly, Walt watched as the man thrust the knife into Gerry's throat.
The mill-owner looked at her unbelievingly, and laughed his boisterous laugh.
Ah, Reader, smile not unbelievingly, as you smiled but a few years past.
Crossing the bridge we are swiftly, unbelievingly, on the Dowie Dens of Yarrow.