Note: This takes place after a key scene in issue #15.
The family has just had its big meeting, and Bruce has once again confined Damian to the Batcave, as someone needs to man the HQ at the batcave... Speaking to his dog Titus, Damian has other plans, and begins to investigate where Alfred was abducted, eventually finding some hyena markings on the premises, leading him to the zoo.
Look... let's just skip the foreplay, Damian falls prey to Joker, and lands in a trap, as he finds himself in a big ol' Robin egg, as Joker plays about in his cage.
Like the Catwoman issue that tied into the event, this is a lot of talking, albeit while Damian takes a few swings at Joker, so it's a bit of a tough issue to write up, if I want to avoid explaining every single page and what is said in detail.
Essentially, Joker runs down what he thinks Robin means to Batman, and vis versa, hinting at quite a few things, such as how Batman is such a large father figure to Robin, and what not. It all ends with Joker revealing he knows what Robin's biggest fear is, that he'll be responsible for the death of Batman, his father figure. So Joker has set up a little game, and a Jokerized Batman emerges from a pit of maggots, ready to fight Robin... or so we think...