QUOTE : Welcome back, Ben,” Erica said. I started in surprise before realizing the voice was coming from inside my head. Alexander had slipped a two-way radio into my ear. There were lots of people out and about. The enemy had taken my cell phone, but I put my hand to my ear and pretended to be talking on one anyhow. No one gave me a second glance. Virtually everyone else was on a cell phone themselves. “Can you hear me?” I asked. “Loud and clear,” Erica replied. “Where are you?” “Still on campus, looking into things. But I need you to tail someone for me.” “Chip?” “No. I think he’s clean.” “What? But—” “I’ll explain later. Right now I need you to go after Tina. She’s the mole . . . and she’s on the move.