Even Robin Couldn't Stop The Bat and The Cat
Perhaps because he's the new kid, Duke doesn't display any kind of resentment regarding Alfred's announcement, either. This is a little more expected than Dick's seeming indifference, as Duke has largely known Selina as an ally to Batman – and possibly even more, if his detective skills truly are as keen as his mentor's. In fact, Duke may very well be the only of Bruce's close confidants to actually see this surprise coming. In reference to Jason's finger-pointing, though, Duke deflects and gestures towards Damian, sarcastically reminding Jason who currently bears the identity of Robin.
The youngster Damian is emotionally impacted the most, possibly due to his age but also likely because he is Bruce's only biological son among the group – and therefore the only one who stands to inherit a new stepmother. Damian Wayne, in fact, is quite possibly being on the cusp of being the only DC Comics hero to have two supervillain moms.
What About Damian Wayne's Mom, Anyway?
Alfred's announcement to the Bat-family on behalf of Bruce was necessitated by Batman and Catwoman's absence – an absence created by the couple's sojourn through the desert toward a nation known as Khadym. Their mission, though, as Alfred also reveals, is in violation of an international agreement, and stands to become a global incident – the kind requiring Justice League intervention.
Why would The Bat and The Cat risk a possible war by illegally entering a sovereign nation? As Damian deduces, his father and future stepmom have ventured to that faraway country because Batman has learned that it's the current secret location of Damian's mother and Batman's onetime beloved, Talia al Ghul.
That Moment When the New Fiancé Is About to Meet the Ex
Yet to be revealed, though, is why Batman and Catwoman would seek out Damian's mom in the first place. It could be that Batman felt that the upstanding thing to do out of respect for his son was to inform the boy's mother that he was getting married, and that a 15-hour horseback ride through the desert was the most efficient means to achieve that.
It's likely that Batman also seeks some form of closure with Talia, though, and possibly some degree of consent – after all, the less drama brought into a marriage, the better. Damian will have a new mom in the house, and while it's hard to picture Selina trying to make the young superhero brush his teeth and do his homework before bedtime, informing the daughter of Ra's al Ghul that his grandson will be getting a stepmother might be a good way to either forestall said drama -- or to get an inevitable and probably violent confrontation out of the way ahead of time.
Or, maybe it's Selina that wants to have it out with her predecessor, to establish her claim to Bruce and formally steal his heart away from Talia, an act that's well in keeping with the mindset of a thief who doesn't like to share her goods. It's Selina who dispatches Khadym's Justice League-appointed guard – while shown to be move motivated by brevity, Bruce's apparent desire to remain uninvolved points towards the notion that this trek is Selina's idea, not Bruce's. When the new girl wants to meet the old one, it's often in the guy's best interests to lay low, anyway.
"Rules of Engagement" is therefore a fitting title to the new story arc, as Bruce and Selina's engagement is one that has its own rules, and requires others to be broken. More of these rules are set to be established, or ignored, in Batman #34, the arc's second chapter, on sale November 1.
Oh, and for those who might have been wondering, Ace the Bat Hound makes an appearance, providing his very own reaction to Alfred's announcement. Grant Morrison's Bat Cow gets a mention as well, confirming that the most important new character of the New 52 era has safely made its way into DC's Rebirth!