It's the 15th century in jolly ol' England, and the air is thick with royal hullabaloo. King Edward IV (Ian Hunter) has snatched the throne away from the delusional Henry VI (Miles Mander), but further treachery still brews behind the scenes. Richard, Duke of Gloucester (Basil Rathbone), has his eyes on the kingdom and will resort to the most lowdown methods possible to seize control. With the assistance of sadistic executioner Mord (Boris Karloff), Richard has gruesome fates in store for those next in line, including his own brother, the Duke of Clarence (Vincent Price). But as Richard moves closer to the crown, an exiled subject (John Sutton) plots in secret to end the tyrant's reign before it begins.
Right about now, you're probably interested in where the whole horror aspect figures into Tower of London. Truth be told, I'm still trying to figure that out, too. All things considered, it's a solid film, but it doesn't quite fit into Universal's thriller pantheon. I'm guessing Karloff's presence played a big part in its categorization, not to mention his character's knack for enjoying his job a little too much. Plus, Rathbone's Richard is one ruthless mofo, knocking off potential successors by way of everything from stabbing to drowning in a vat of mine. But Universal played up the historical horror angle more so in films like The Black Castle and The Strange Door. Tower of London has nary a hint of exploitation to its name, although the story's constant backstabbing and shifting alliances do allow for ample intrigue.
In any case, pound for pound, Tower of London has one of the best casts in any Universal chiller. Of course, there's Karloff, suitably menacing as club-footed madman Mord, but other familiar faces put in an equally good show. Rathbone appeared in just a few horror flicks (spending most of his Universal tenure as Sherlock Holmes), but he turns in a pitch-perfect performance here. He plays Richard as a perfect schemer, a man charismatic enough to mask how he's practically snarling beneath the surface. The film's meat stems from just how low he'll go to claim the throne, reaching a fever pitch when he targets his young nephews for assassination. No stranger to horror himself, Price also shows up in a role that's brief but impressionable, thanks to a memorable scene in which he engages in a deadly drinking game with Richard. The remainder of the cast is fine enough, though their basic medieval material is greatly overshadowed by Richard's homicidal goings-on.
Tower of London suffers a few kinks in the armor (some rushed editing, battle sequences on par with Ren Faire re-enactments, etc.), but it holds its own rather well. Though I wouldn't call it straight-out horror by a longshot, it does work such elements into the plot's costume drama structure with relative ease. Besides, any film that gets you to fear some of classic horror's most famous icons without pounds of make-up involved is aces in my book.