Russell Horton was a ubiquitous actor in Mystery Theater and his distinct voice was very identifiable.  Though he portrayed a huge range of characters in many episodes - often performing multiple characters in a single play - he was at his best playing the competent and cerebral 'everyman.'  Among his best and most involved performances was as captain of a hijacked jetliner in 'Sierra Alpha 638.'  In that episode he also played the co-pilot of the search and rescue plane.  Cheers Mr. Horton - and THANK YOU!