Artemis joins the team this week, and the arbitrary nature of her arrival causes quite a few problems in the drama department. In addition, she’s rather thin soup personality wise, with a standard-issue helping of bad girl sass to contrast with Miss Martian’s sweet-natured wallflower. To make up for it, “Infiltrator” hands her a giant pile of intrigue: some of it involving the ninjas who serve as the bad guys du jour, some of it involving Speedy/Red Arrow who views her as a replacement. Director Jay Oliva provides the usual cocktail of solid action, and the mystery surrounding the new member holds its own pretty well. While it doesn’t stand as a series high point, it still has the chops to get the job done.