"A new video's been uploaded." Laura raced into Alastair's office.

He set the phone down and gave her his full attention. Laura rounded the desk and opened the web browser. It had been three days since the last video and he hated to admit it, but Luna had been right. Was she aware of the video?

Laura clicked on the video and the grainy footage started. The two terrorists were in their masks again and he scowled at them.

"Good Morning, London." The first figure said.

"We would like to offer you a riddle. We'll start off easy so you can play our game." The second one said.

"I can only live where there is light, but I die when the light shines on me. What am I?" The first said, and Alastair detected a hint of mocking in the tone.

"Should you fail to get this riddle then the whole of central London will be plunged into darkness and sparks will fly."

The screen cut to black, leaving Alastair and Laura staring back at their own confused faces. Alastair leaned back in his chair, thinking. Sphinx had stated this riddle would be easy, but it didn't sound easy.

Someone knocked on the door and both officers looked up to see Luna standing in the doorway.
"Have you seen the video?" She asked.

"Yeah, just watched it, actually." Laura replied.

"We must first deduce if there are any events over the weekend that would create a large amount of light." She started.

"There's a street party on Picadily this weekend." Alastair said.

"I believe the answer to the riddle is a shadow," Luna said. "A shadow lives in the light, but dies if light is cast upon it."

"That's brilliant. So, how do we let them know the answer." Laura asked.

"We fight fire with fire." Alastair replied, standing.

They used his office and set up a camera, connecting it to the internet to create a live feed. Alastair had some things he wanted to say to the terrorists, but Luna stopped him.

"I should address them. I know them well, detective." She smiled then.

She sat in the chair opposite the camera, not smiling or blinking for a few seconds before she cleared her throat, delicately.

"Hello Sphinx, or should I call you Subjects 5963 and 7453. I will play this game with you starting today. The answer to your riddle is a shadow." Luna said, grinning.

Subjects? Alastair stared at the girl as she spoke. A subject was something used in a lab or experiment. Were these terrorists part of some kind of twisted experiment?

"This game you're playing is dangerous and I will stop you." Luna finished, standing and dusting off her skirt.

Laura turned the camera off and they waited for a response. They didn't have to wait long though.

"Alastair, something's wrong with the computer." Laura called.

Alastair and Luna rushed over, standing round the desk. A video appeared on screen and Alastair realised the two terrorists were streaming directly to them.

"Hello again, Subject 1278. We're so pleased to see you again. You solved the riddle. However, we will still plunge the city into darkness."

The feed cut and Alastair stared blankly at the screen. He suddenly realised something and tapped Laura on the shoulder.

"Trace their IP address." He said, and Laura started typing things in.

Luna scoffed then, "Do you assume Sphinx are imbeciles. You will be unable to locate them."
Laura swore then and slammed her fist onto the keyboard.

"What's wrong?" Alastair asked.

"I tried to trace them, but can't. Not only that they've hacked into the police mainframe and cut the internet." She snarled.

"They are quite sufficient, are they not?" Luna giggled.

"Luna, I need to know everything about these two. No more secrets." Alastair snapped, and she grinned.

Someone knocked on the door. Alastair turned and the door flew open. Another officer was standing in the doorway, looking flustered.

"Sir, the entire phone system is down." He said.

Laura stepped away from the screen and her lips parted as though to speak, but no words came out. Luna was still standing next to Alastair, and he noted that she didn't look too bothered by this news.

"They are punishing you." Luna grinned.

"Punishing me?" Alastair asked.

"You involved me in this game and Sphinx are displeased by this." She continued.

The system eventually came back online and Alastair went and sat at the his desk, sinking into the chair, sighing heavily. He glanced at Luna.

"I must depart now, detective. Fear not, I will discuss all I know regarding Sphinx."

Notes

Short chapter, bigger one tomorrow :)