Christopher Brown
From Tardis Wiki, the free Doctor Who reference
Christopher Brown played Marriner in the Doctor Who story Enlightenment.
His turn on Enlightenment was not the first time he had played a mild adversary of Peter Davison's on BBC One. Just a few years earlier, he had a recurring role on All Creatures Great and Small, in which he played a veterinary student whose study habits greatly outshone Davison's Tristan Farnon.