Justin Bieber's candid revelations about drugs, depression and his life struggles. Plus, we're cruising with a "Top Gun" sequel co-star as she dishes on her wild ride with Tom. Then, ET takes you inside the "My Best Friend's Wedding" reunion with the cast. Plus, Grammy Host Alicia Keys dishes on her duet with James Corden! And, ET's "Throwback Thursday" runs down the first time Grammy winners. Entertainment Begins and Ends with ET.