Lancelot, Merlin, and the gang are all here, but don't expect this adaptation from director Antoine Fuqua (Training Day) to resemble the cartoonish versions of olde. ''This is where the myth came from,'' says producer Jerry Bruckheimer. ''It takes place in the fifth century. It's primitive.'' So look for lots of damp gray combat as the Knights of the Round Table try to rescue an aristocratic Roman family against the backdrop of the Saxon invasion of Britain. ''They're basically given the mission from hell,'' says the king himself, Clive Owen. Also on board: Horatio Hornblower's Ioan Gruffudd (Lancelot) and The Hours' Stephen Dillane, whose Merlin is less magic than maverick, leading a rebel gang that menaces the knights. And what would Lancelot be without his Guinevere? Especially when she's Pirates of the Caribbean's Keira Knightley, who reunited with Bruckheimer to play another blue-blooded heroine not afraid to do some dirty work. ''She's fearless,'' says the producer. ''I mean, in this one battle scene -- my God -- she scares you!'' Beats wearing that pesky corset.