This time of night, the docks were nearly empty. Batman parked the Batcycle behind a shed. He slinked through the shadows, not knowing what he was looking for. He had come here only on a hunch.

Up ahead, near one of the piers, a boat was docking. There was some excited shouting coming from the crew. A couple of men were dragging a third man from the boat. He seemed hurt.

In the distance, Batman could hear the wail of an ambulance siren.

He rushed to see what was wrong.

“Batman!” one of the crew shouted.

Batman looked down at an unconscious man. He was bound tightly in super-strong fishing line.

“What happened to him?” Batman asked.

“We don’t know,” the crewman replied. “He was tied to the dock.”

“We almost hit him with our boat when we came to shore,” the other crewman said.

Batman bent down and pulled the gag from the man’s mouth. The man moaned in pain. Examining him, Batman noticed he was breathing okay, even though he was unconscious. The man was also very sunburned, so he had probably been tied up all day in the sun.

Batman cut the man loose with a Batarang and stayed with him until the ambulance arrived. Afterward, he radioed Alfred.

“Find anything, sir?” Alfred asked.

“I’m not sure, Alfred,” Batman replied. “There was a man tied up to one of the docks. But he is unconscious and no one here knows him.”

Batman added, “Alfred, could you patch me through to Detective Montoya?”

“Right away, sir,” Alfred said.

A second later, Batman heard Renee Montoya’s voice on his headset. “We haven’t found any clues, yet,” she said. “We even tried locating the technician responsible for setting up the alarm system, but he seems to be missing.”

“Since when?” Batman asked.

“Since this morning,” Renee replied. “His boss says he was called away on some special project, but no one is sure what it was about.”

“There was a man tied up at the docks,” Batman said. “He could be the missing technician.”

As he was talking into his headset, Batman looked down at his feet. He noticed the man’s gag lying there, a crumpled piece of paper. Batman picked it up and flattened it out. It was a newspaper article about the new coral reef tank at the aquarium. Tonight was a special showing for the aquarium’s wealthy donors. Many of Gotham City’s richest and most powerful citizens were going to attend.

“Detective Montoya,” Batman said. “Can you send someone to the hospital to talk to this man when he regains consciousness? He may be able to tell us who’s behind these events.”

“Okay, Batman,” Montoya replied.

Tucking the piece of paper away, Batman sprinted to the Batcycle. He revved its engine and sped away into the night.

• • •

At the aquarium, the Joker stood on the stage with a remote in his hand.

“Okay, folks,” the Joker said to his captive crowd. “If you aren’t going to laugh at my jokes, then I’ll have to find other ways to entertain you.”

He pushed a button, and Robin plunged into the tank.

The people in the audience shouted and begged for the Joker to release Robin. But it was obvious that they were tired. Their voices were hoarse from hours of laughing at the Joker’s jokes.

“Um, Mr. J.,” Harley Quinn pointed to the tank. Sharks and electric eels swam near Robin. “The party’s not over yet.”

“Okay,” the Joker pouted.

He pushed another button on the remote. Robin was yanked out of the water, gurgling and sputtering.

“Let’s try another one,” the Joker turned to the crowd. “What’s a shark’s favorite sandwich?”

The crowd stared, dumbfounded, at the Joker. No one responded.

“Come on, people!” the Joker screamed.

“The Boy Wonder is about to become a shark treat,” he threatened.

Still silence from the crowd.

“I know! I know!” Harley raised her hand. “Peanut butter and jellyfish!”

The Joker chuckled. A clown raised the sign to laugh, but the crowd only let loose a half-hearted chuckle.

“Not good enough,” the Joker yelled, pushing a button on the remote.

Robin took a deep breath before plunging into the water again. He didn’t struggle once he was submerged. He didn’t want the sharks to mistake him for prey. If he thrashed around, they might think he was an injured seal or fish.

Robin backed up against the reef. He tried to use the coral to cut the rope.

Robin had to be careful because the coral was razor sharp. If he cut himself, the sharks would smell the blood and attack. He also needed to keep clear of the electric eels. They could deliver a deadly shock if he touched one of them.

“Can I try a joke, Mr. J.?” Harley asked.

“Sure,” the Joker replied, pushing the button. Robin was yanked out of the water.

Harley turned to the crowd. “What do you get when you cross an electric eel with a sponge?” she asked. After a brief pause, Harley shouted, “A shock absorber!”

No one laughed.

“That’s curtains for the Boy Wonder,” the Joker said, about to push the button.

“Wait!” Harley Quinn said. “A very special guest will be showing up soon!”