When Captain Burnham and the Discovery get assigned a red directive mission, she and Captain Rayner don’t quite sync up. But when Book is called in to help with The Chase, they track down the thieves and learn that this season’s MacGuffin was already opened by Fred. Why don’t more parents register for airline chair? What’s required to rent a shielded dirt bike? Which characters will season 5 be pivoting to full time? It’s the episode that wants a text before you call.