It was evening in Cartoon Network City, everyone was sleeping except for certain people Mike, Jo, and Sky were outside since it was the full moon. They were peeking behind the bushes and saw Peter and Lois having a picnic.
"Ugh, just looking at those two makes me sick." Jo groaned.
"Ignore them, remember why we're here." Mike told her.
"Why are we here again?" Sky asked. "Are we gonna hunt someone?"
"No, but I've been having strange dreams lately about werewolves." Mike said.
"Good or bad?" Sky asked her cousin.
"Bad." Mike replied.
"How bad?" Jo asked.
"Robbing the jewelry stores, turning other people into werewolves, attacking innocent people..." Mike listed.
"That is bad..." Jo said. "Do you know who it is?"
"I don't think so..." Mike shrugged. "We might have to do some investigating, like detective work."
"You can count on me, Mike." Sky promised.
"Same here." Jo added.
"I also told Phil, Lil, Reggie, and Arnold too," Mike then said. "They're gonna help us out."
"I get Phil, Lil, and Arnold, but why Reggie?" Sky asked.
"I bit her so that she could be in the Netherworld Tournament," Mike explained. "She can't change into a wolf, but she still has the same abilities that one would have."
"How'd you manage to do that?" Jo asked.
"Drell made a cure for her, but with side effects." Mike explained.
"Of course." Jo scoffed.
"All right, guys, let's go." Mike said.
Jo and Sky nodded and followed Mike as they did a search around town much like Batman would check out Gotham City after bedtime for many citizens.
"So far so good." Sky commented.
"I don't think so," Jo growled after sniffing the air. "Look!"
The three tomboy girls turned around and saw a black-furred werewolf robbing a jewelry store.
"Of course..." Jo rolled her eyes. "All right, let's go!"
"All right, mutt, drop that jewelry!" Mike demanded.
The werewolf growled and ran away from its kind.
"Get back here!" Mike demanded.
"This won't be easy," Sky said to herself. "Are you sure we can solve this without superheroes?"
"We're werewolves too, cous, we can handle it." Mike reassured.
"Well, all right, if you're sure." Sky shrugged.
"I'm sure," Mike confirmed. "Let's go."
Mike and Jo went on ahead. Sky hesitated at first, but she sighed softly and soon followed after her fellow werewolves. The werewolf was running from the trio, jumping from roof-to-roof.
"Stop, thief!" Sky yelled out.
The werewolf growled and continued to run away from them.
"So that's how they wanna play it, huh?" Jo huffed.
"Then we'll play that game too," Mike replied. "Let's go."
"Right." Jo and Sky agreed.
The werewolves continued to chase each other. The unknown werewolf grabbed a car lifted it up, and then threw it at the trio. Jo grabbed the car and threw it right back at the werewolf. The other werewolf dodged it and went into the alley, disappearing somehow.
Sky ran into the alley and looked around. "They're gone!" she then told the jockette and her tomboy cousin.
Mike and Jo sniffed the air and growled again.
"Now what?!" Jo asked.
"We wait," Mike replied. "Besides, we're going with Mystery Inc to the circus in Atlantic City. Phil, Lil, Reggie, and Arnold are gonna come with us too."
"We'll need the rest for the trip, but I wonder what the bad werewolves need that jewelry for?" Sky pondered.
"Who knows?" Mike shrugged.
"Who cares?" Jo scoffed. "It's a crime and however did it will suffer from ME!"
"Easy there, tiger; we'll get them," Mike said before she pulled out her cell phone to dial a certain number. "I should call the other guys to see if everything's going okay over there."
Meanwhile, at Nicktropolis, Phil, Lil, Reggie, and Arnold were the only ones up and about at this hour to make sure that everything was okay.
"So far so good." Reggie commented.
"I'm tired." Phil yawned.
"Surprised you still are after falling asleep when Dad was scolding you for breaking his favorite wedding present." Lil scoffed.
"Whose fault was that, Lillian?" Phil huffed. "You're the one who kicked that soccer ball too hard!"
"Guys, no fighting, we have a job to do." Arnold scolded the DeVille twins.
Phil and Lil murmured in agreement. Reggie then sniffed the air and looked around.
"What's wrong?" Lil asked her.
"Something is not right." Reggie told them.
"Is it someone from the Ghost Zone?" Arnold asked his girlfriend.
"If it's an alien from the night invading us all, call Jenny." Phil deadpanned.
"No, it's-" Reggie began.
Like in CN City, another werewolf was robbing the jewelry store.
"Something like that." Reggie then finished.
"Come on, we gotta stop that thief!" Arnold told the others.
"Let me see if I can catch the thief." Reggie decided. With her new speed, due to being a werewolf before, she began to chase after the bad werewolf invading their town.
The werewolf snarled as they continued to run with the jewelry.
"STOP, THIEF!" Reggie demanded as she then jumped high in the air and was about to pounce onto the werewolf.
The werewolf grabbed a trash can and threw it at the tomboy, but Reggie punched the trash can, breaking it in half. Phil and Lil soon came in, joining Reggie and Arnold to stop the loose werewolf in Nicktropolis.
"All right, flea bag, you wanna deal with your own kind?" Lil snarled.
The werewolf growled and ran away from the kids, jumping from roof-to-roof, disappearing into the night, but not before howling at the moon. Lil, Phil, Reggie, and Arnold took a look around and the werewolf seemed to be gone.
"Well, I don't know how that happened, but we're alone now." Arnold told the others.
"Next time we see him, it won't be pretty." Phil firmly promised.
Lil's cell phone soon rang and she answered it. "Hello? Oh, hey, Mike, what's up?" she then greeted.
'Is everything okay over there?' Mike's voice asked.
"Well, we just encountered a werewolf robbing the jewelry store." Lil informed.
"What?" Mike asked. "That's strange."
"I know!" Lil replied. "What if people trace it back to us?!"
"No, I mean that's exactly what happened over here!" Mike told her.
"What?" Lil asked.
"A werewolf was robbing our jewelry store too!" Mike told her. "Me, Sky, and Jo tried to stop him, but he disappeared too!"
"That's strange," Lil replied. "What can we do about this?"
"Look on the bright side, we'll be at the circus later," Mike replied. "Hopefully it'll turn out better than that time Sky and Jessie were forced to join from that evil ringmaster with that baby elephant with the big ears."
Sky shuddered in memory from that.
"And we'll be there in the morning." Lil promised.
"I guess the gang is gonna have to have a werewolf mystery during this circus." Mike told her girlfriend.
"And we'll be there too to help them out." Lil replied.
"All right, guys, we'll see you tomorrow," Mike said. "I love you."
"I love you too, bye." Lil replied before hanging up.
Unknown to them, Otto, Twister, and Sam were behind the alley, listening in on the conversation.
"And we're going with Mystery Inc too." Otto decided.
"Uh, we are?" Sam asked nervously.
"Yes, Squid, we are." Otto replied.
"But did you see that werewolf?!" Sam yelped.
"I don't care, we're going." Otto replied.
"No way, you can't make me, I'm out of this!" Sam refused and folded his arms. "No way!"
"Fine then," Otto huffed. "I guess I'll be telling Macie all about your Sassy Cat collection."
"You wouldn't dare!" Sam gasped.
"Try me." Otto glared.
"All right, fine..." Sam sighed in defeat.
"Good to have ya on board, Sammy boy." Otto smirked as he put his arm around the geeky boy.
"Spinelli said that she would kill Otto if anything bad happened to me." Twister smiled innocently.
"Twist, shut up, I just got over the nightmares!" Otto scolded his idiotic best friend.
And with that, everyone went home to get some sleep until tomorrow, for an new adventure that was coming.