A Case of Identity (S02E09)

To rein in Inspector Lestrade's reckless behavior and chaotic police pursuits, Grayson pairs her with a new partner who's just graduated from the academy. However, as security at Scotland Yard begins to falter, the rookie's clumsiness leads to a series of blunders that disrupt everyone's efforts. But is he truly the inexperienced officer he appears to be?