Jennifer Garner will spend her summer vacation from ''Alias'' wearing a skimpy skintight costume and using her lethal skills to fight double-crossing bad guys. Her busman's holiday will be the shoot of ''Elektra,'' the long-gestating ''Daredevil'' spinoff, which Variety reports will go before the cameras in May. Rob Bowman (''Reign of Fire'') will direct the feature, whose storyline will be drawn from the graphic novels ''Elektra: Assassin'' and ''The Elektra Saga.'' In the film, Garner's hitwoman will go up against the Hand, the organization that trained and betrayed her. Still to be cast is veteran Marvel Comics character Stick, a martial arts trainer. As far as making an actual ''Daredevil'' sequel, Variety reports that 20th Century Fox is keeping its options open, but we doubt whether even the sonar skills of Ben Affleck's sightless superhero could detect a second film on the horizon.