Suitable for reading age 8.6 years. Mark was holding his knee. His trousers were torn, and I expected to see loads of blood where he'd cut himself - but there was none of that. Mark's skin was ripped back and, inside his knee, there was a long, metal bar and loads of coloured wires. Al loves hanging out with his new friend Mark Tenby at school. Some of the other students think he's a bit odd, but Mark and Al have so much in common. It isn't until a game of football goes wrong that Al starts to understand quite how odd Mark really is... Why does he have wires where his knee should be? And why does he keep getting calls from 'Mother'?show more