Based on Mark Twain's highly acclaimed book Following the Equator, On the Trail of Mark Twain With Sir Peter Ustinov: A Riddle at Every Turn -- Vol. 3 is the third episode in a four-part PBS travel documentary series. The 60-minute program features actor and journalist Peter Ustinov traveling to Sri Lanka and India. Highlights include visits to Darjeeling and Bombay as well as a boat trip down the Ganges River. Other tapes in the series include: On the Trail of Mark Twain With Sir Peter Ustinov: Isles of Paradise -- Vol. 1, On the Trail of Mark Twain With Sir Peter Ustinov: Beautiful Death -- Vol. 2, and On the Trail of Mark Twain With Sir Peter Ustinov: Such a Wonderful Thing -- Vol. 4.