Fox’s Empire is not showing any signs of weakening — just the opposite. Wednesday’s third episode of the Lee Daniels soap went up again in the ratings, jumping to 10.9 million same-day viewers (versus 10.3 million last week) and notching a preliminary 4.3 rating among viewers under 50 (versus 4.0 last week), easily making it Wednesday’s No. 1 show with young viewers. It’s very rare for a new broadcast series to build an audience in its second outing (as Empire did last week), and rarer still to grow in week three. Things could still change, and viewers could lose interest, but for now, Empire is shaping up to be not just a hit — but a bona-fide phenomenon.