Warning: SPOILERS for Batman #54

Nightwing isn't just Batman's first sidekick - he's also the most important. Because no matter what, the Dark Knight will always need his Dick Grayson. At least, that's what Batman #54 tries to prove to DC readers.

Batman's relationship with his first Robin has been largely absent in the DC Universe since DC Rebirth. Instead, the main Batman series has focused on Bruce Wayne's own pursuit of happiness with a now-failed romance with Catwoman. Bruce is dealing with the break-up by returning to the classic Batman costume, but Issue #54 finally addresses the lack of certified bromance in an enormous way.

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Nightwing has appeared before in Tom King's Batman series, most notably filling in as a temporary Batman while Bruce Wayne was on jury duty. Batman #54 is something different. The first part of a two-part story, the issue is an examination of the duo's relationship - both how it began, and how it works now. With Bruce Wayne's trying time on jury duty over, Nightwing and Batman team up to take on various Gotham criminals. Using flashbacks to show the true depth of their lifelong connection (for Dick, at least).

The devoted Batman fans will be pleased to see Batman #54 establish Bruce took custody of Dick when he was still a young child, as other stories have blurred the line towards Dick's teenage years. More importantly, the flashbacks underscore how similar Batman and Nightwing's origins are - and how differently they respond to trauma. The difference in how Bruce and Dick respond to their situations (and the reason their relationship is so important) comes about in the present day story.

The flashbacks show Bruce unwilling to give up on the young Dick, relentlessly trying to reach him. In the present, the adult Dick Grayson does the same for Bruce, adrift in loss. Batman claims to be "fine" over his break-up with Selina Kyle but is fooling nobody. Now, it's Dick's turn to refuseto let up, or let Bruce isolate himself in grief.

It's a compelling contrast for a single story, but also demonstrates the dynamic duo's unwavering character. Nightwing is always able to reach and connect to the man behind Batman's mask. Nightwing is the one hero who can always bring out the humanity in Batman. Which is a good thing, since a Batman who's disconnected from his emotions is a dangerous - as in potentially world-ending - figure. But at the same time, this story offers an interesting commentary on the reason Catwoman left Batman at the altar.

She feared a happy Batman couldn't do his job properly. Nightwing and Batman's father-son dynamic is proof that Batman can have love in his life and still be the Caped Crusader. And a reminder, if one was ever needed, that Nightwing will always be there to pick up his mentor when he's down.

More: Batman is Finally Going Back To His Classic Costume

Batman #54 is available now from DC Comics.