David's grown up into a good kid. He knows he could depart his life at any instant, and he doesn't want to leave bad feelings behind.
Meanwhile we're introduced to a weird relationship between Gerard and Daphne, and we end with Gerard apparently planning to strangle Quentin. Gerard was killing people with heart attacks - or something - in 1995, but either he hasn't yet developed that capability, or else he's just having fun with Quentin.
Julia knows something is wrong, but she doesn't know just how much is wrong. It's all very insidious.