Bruce was busy working at the Bat computer when he heard a splash breach the surface of the cave’s waters, breaking his concentration. For a few seconds, he rationalized it as water dripping from the stalagmites or an auditory hallucination from three sleepless nights in a row. Both were equally likely possibilities.

Still, there was a third option he was disregarding—the rescued seal pup somehow escaping its enclosure. A few days ago, he had rescued a seal pup from Penguin’s enclosure with Robin and had planned to free the seal back to Gotham Bay as soon as possible. Or leaving it with a reliable rehabilitation centre—Bruce had more than sufficient resources to find a suitable home. But Damian had dug in his heels, refusing to give up his newly rescued pet. Bruce, perhaps weakened by sleep deprivation and sentimentality, agreed to keep the seal pup around.

If only for a few days, until the wound on its’ tail healed properly. He wasn’t about to keep a wild animal hostage in the cave.

Bruce didn’t move. He kept his eyes fixed on the scrolling lines of code on the center monitor, but his hand moved with practiced invisibility to a sub-menu on his gauntlet.

He hadn't told Damian, but he’d installed motion-sensitive thermal cameras around the rehabilitation tank three hours ago. The "seal" had been displaying behavioural anomalies that Bruce couldn't ignore: it understood complex commands too quickly, and its eyes held an almost human-like intelligence that seemed to track the occupants of the cave with open wariness. As if the pup was trying to decide whether or not to trust them.

Bruce didn't turn around. Instead, he brought up a localized feed in a small, minimized window.

On the screen, the seal pup wasn't swimming. It had hauled itself onto the slick rock ledge, but it wasn't sunbathing. No, instead, the pup was twisting around to try and sit upright like a human. Bruce realized it was unzipping.

There was no zipper, of course, but the skin along the spine seemed to ripple and part like wet silk. A small hand reached out from within the dark fur, fingers splaying against the cold stone of the Cave.

Bruce felt the breath hitch in his lungs. He had fought gods and monsters, but the sight of a human child emerging from a seal pelt was hauntingly novel.

Just what were they? And had Penguin known of their true nature when he captured it—no, when he captured them?

His footsteps were almost silent as he stood from his chair, his cape billowing out behind him as he walked towards the seal’s—if he could still call them that—enclosure. He had long unmasked in the sanctuary of the bat-cave, leaving behind the man under the cowl.