The Man in the Iron Mask(1968)

A completely lost BBC1 miniseries adaptation of Alexandre Dumas' 19th century historical adventure novel of the same name. Years have passed since the Three Musketeers, Aramis, Athos and Porthos, have fought together with their friend, D'Artagnan. But with the tyrannical King Louis using his power to wreak havoc in the kingdom while his twin brother, Philippe, remains imprisoned, the Musketeers reunite to abduct Louis and replace him with Philippe.