*NOTE* You should probably read Batman #17 before this. Some "Death of the Family" spoilers are contained pretty early in this post.
So Bruce and Damian return to the Batcave, greeted with meals by Alfred (told you) but Titus seems to be the most receptive to the food. Calling it a night, Bruce, Alfred and Damian all go to bed, and shit goes crazy!
In Damian's dream, there are two versions of himself, the Wayne Damian and the Al'Ghul Damian. As the Al'Ghul one watches on from a submarine as everyone from Nobody, Talia, Dick, Jason and the Joker drown, the Wayne version of himself comes up to him, and tries to remind himself of who they really are, Wayne first, Al'Ghul second. The Al'Ghul version of Damian starts to realize that as he sees Alfred struggling for air in the water. The site of Alfred drowning is disturbing enough to wake Damian up, where he finds a Robin on the foot of his bed. He follows the robin into the manor, and then hears his father ringing for him. In the study, he finds his father sitting in that chair, being fed on by a giant bat, and then Damian really wakes up. BRRRWWAAAAAAAAANNNN.
Let's jump to Alfred's dream, where he's watching Thomas, Martha and Bruce getting ready to go out, but then he wonders into the Batcave where he finds Joker going at it with a hammer to the whole Batfamily. What does Alfred do? BLOWS JOKER'S HEAD OFF WITH A SHOT GUN, THAT'S WHAT. Alfred then wakes up, and though clearly a bit disturbed, goes back to sleep with a smile.
Meanwhile, in Bruce's dream, he's with older versions of his parents, and the paper boat motif from the first issue comes back, as the boat gets bigger, and many of Batman's foes try and knock him off, until a giant whale swallows the boat whole, knocking him into the water. Sinking into the water, Bruce is saved by his son's hand reaching for him, leading him to wake up. Bruce then goes to check on Damian, before going back to bed.
We then see a shared (maybe?) dream both Bruce and Damian have of them kicking ass. When Bruce tells Damian it's a dream, he mentions how it's the first one he doesn't want to wake up from.