“What is this stuff?” MacGyver used his Swiss Army Knife to chip a piece off the wall, turning it over in his fingers.

“I was hoping you’d know.” Kate Murphy turned to scan the alley, aware of unseen eyes watching them. She turned back to find MacGyver sniffing the piece of hard foam and holding it up to the light for a closer look. “Whatever it is, it made a helluva mess of one of the Canyon Crawlers this afternoon.”

“Canyon Crawlers? That’s really a name?” MacGyver stood back, looking at the splatter of hardened slime on the wall. “Whatever it is, I’m pretty sure it was fired from a gun – the splash is the wrong shape for something that’s been thrown by hand.” He put his hands into his jacket pockets. “What’d it do to this kid?”

“Glued him to the wall.” Kate caught MacGyver’s incredulous stare. “No, really! Glued him right to the wall. We had to cut some of his clothes and a chunk of hair off him to get him loose. Also, wherever it stuck to his skin, it had burned him. Nasty stuff.” She shuddered.

“Burn like a chemical burn, or like it was hot?” MacGyver examined the scraps of cloth stuck to the mess.

“Hot.” Kate looked around the alley again, then touched the solidified slime. “He said it was hot.”

“OK.” MacGyver straightened up. “I’m going to take this back to Phoenix and see what I can come up with. I’ll call you, OK?”

“OK.” Kate frowned at the slime. “I’m going back to the hospital, see if I can get anything more out of this kid.” She hitched her bag up on her shoulder and walked out of the alley with MacGyver walking alongside, lost in thought.

“Gotcha.” MacGyver wrote on the bottom of his notes and held the paper up for Seeley to see. Seeley glanced at the paper and shrugged.

“ Chemistry’s not really my thing.” He handed the paper back to MacGyver, who shook his head in mock sorrow.

“Really? Nothing at all?” He held up his test tube. “It’s kind of like superglue, but with some modifications. The sample was full of air bubbles, so the glue’s been changed to make it deliver as foam.”

“Like a fire extinguisher.” Seeley leaned forwards, picking up the remaining piece of slime. “So how do you stop it sticking to the gun when you fire it?”

“I’m still working on that part.” MacGyver ran a hand through his hair and shrugged. “Maybe if you could grease the barrel, it would stop it sticking. We found no evidence of a cartridge at the scene, so I guess they didn’t get round it that way.”

“Huh.” Seeley tested the hardened edge with his thumb, finding it sharp. “A glue cannon. One of your new, non-lethal weapons, maybe?”

“Maybe.” MacGyver shook the test tube and held it up to his eyes. “Question is, what’s it doing in the hands of a two-bit gang from South Central?”

“Right.” Seeley tossed the fragment up in the air and caught it. “And also, who else has got one?”

“Hey, watch where you’re pointing that thing!” She wiped at her gang jacket with her hand and glared at Jethro. He levelled the gun at her and grinned over the barrel.

“Bang. You’re dead.” His voice was soft and she backed away, unnerved. Of all the gangers, Jethro was the only one who really scared her. Jethro grinned at her again, his eyes wide and wild. “Let’s go hunting.” He strode out of the kitchen with the gang following him, and Gina heard the door slam behind them.

The recoil on the glue cannon was more than Einstein had thought it would be. Jethro staggered back and was caught by Lonnie, who shoved him forwards with a laugh. Jethro pulled the trigger again, the high-pressure spray tracking the figure running away from them. The glue splattered across the back of his victim’s coat, gluing the long coat tails to the ganger’s jeans instantly. The ganger tripped, sprawling against a dumpster and rebounding off into an oily puddle. He turned over, scrambling backwards as Jethro advanced.

“Not in his face!” Einstein bit his lip as Jethro rounded on him.

“Get him out of here.” Jethro gestured with the gun barrel and Einstein felt Lonnie grab him from behind, a slap rocking his head and making him see stars. Lonnie turned, dragging Einstein away by the collar. Einstein struggled, kicking and gouging. Lonnie released him with a curse and Einstein spun round, just in time to see Jethro open fire on his victim. One long blast of glue stuck him to the cracked concrete, the blast catching him across the chest and face.

Jethro mimed blowing smoke away from the barrel and stepped back into the darkness between the tenements. Einstein heard a car engine slow, then rev and speed away into the night. He ran down the alley to where the stricken ganger lay, clawing at his face. The glue had set, filling his nose and mouth and, as Einstein skidded to a halt, he saw the ganger’s eyes roll up and his frantic efforts to breathe slow and then stop.

How could something as specialised and unusual as this have found its way onto the streets? A theft from a chemicals lab would surely have been reported… He made a mental note to ask Kate if any thefts had come to her attention recently. The intersection lights turned red and MacGyver coasted to a halt. The glue must have been fired with some force to pin the ganger to the wall, like that. That suggested it was under pressure, which in turn suggested some kind of propellant, or that the glue was stored under pressure. The light changed and he accelerated past a garden supply centre, the display of weedkiller spray packs brightly lit in the window. Could you use a similar delivery system for glue? Seeley had seemed sure it would gum up the workings, but MacGyver wasn’t so sure. He turned into his driveway and parked his bike, leaving his helmet hanging on the handlebars. He went inside, pressed the blinking button on his answerphone and listened as he shrugged out of his jacket.

“Mac, it’s Kate. It’s uh… 5:40pm and I’m at Mercy Hospital. Can you come meet me here? There’s something you need to see.” Her tone was grim. MacGyver picked up his jacket again and headed back out.

“Mac, your hi-tech superglue just killed a kid.” Kate scrubbed her hands across her face and through her hair. “Gang fight, most likely; he got a faceful and it suffocated him.” She took a deep breath.

“Where is this stuff coming from?” MacGyver balled his hand into a fist, then let it drop without hitting anything. “Do we have any idea?”

“Matter of fact, yes.” Kate set off down the corridor, motioning for MacGyver to follow. “A truck carrying the glue and the guns to fire it went off the road in last night’s storm and spilled its load halfway down the Hollywood Hills. First though, you mind taking a look at the kid? We haven’t been able to ID him so far and with your Challenger’s Club connections, I wondered if he’d crossed your path.” She paused, her hand on the doorknob. “I hate to ask, but…” She opened the door a crack. “It’s pretty bad, Mac.” MacGyver nodded and stepped past her into the room.

The body lay on a trolley, sheet drawn up to cover the face. MacGyver gently drew it back, staring at the boy beneath. So young… The glue had hardened, a clear, bubbly layer blocking his mouth and nose, sticking his shirt to his chest. MacGyver swallowed hard and replaced the sheet.

“I don’t know him, Kate. I’m sorry.” He pushed his hands into his pockets, hunching down inside his coat. A movement at the corner of his eye caught his attention and he turned.

“What is it?” Kate came into the room, letting the door swing shut behind her. She watched MacGyver crouch down beside the empty bed, watched him extend a hand underneath and then frowned as he helped a small ganger out from under the bed.

“What are you doing there?” It came out louder than Kate had intended and the boy took a step back, lost inside an enormous leather jacket. MacGyver stayed kneeling down, watching the boy.

“Did you know him?” MacGyver’s voice was quiet. The boy sniffed, then nodded. “Do you know who did this to him?” Another nod.

“Can you tell me his name?” Kate watched as the boy’s eyes grew wide and he shook his head. She opened her mouth to insist, but MacGyver shot her a warning look. He turned back to the boy.

“Can you tell me your name?” The boy replied, too quietly for Kate to catch. MacGyver nodded.

“OK, Einstein. Do you have someone at home? Someone who might be worried about where you are?” The boy shrugged, not taking his eyes off Kate. MacGyver sat back on his heels. “Kate, I’m going to call a friend of mine to come get this guy. Gloria from the Challenger’s Club, OK?” he waited until she nodded, then turned back to the boy. “We need to talk to you about what happened here. I know you’re scared, but we have to stop this happening to anyone else. Do you understand?”

Einstein took a deep breath. He understood, but telling them about Jethro was going to get him good and mad. Mad enough that he might go really crazy, and take Einstein with him… He glanced across at the still form underneath the sheet and shivered. He looked up at Kate, then back at MacGyver.

“OK. I’ll tell you.”