Nikki and Detective Matthews were sitting in the lab huddled round Nikki's laptop both staring intently at the screen

"I hope we're not looking at anything naughty" Nikki looked up to see Harry standing behind them

"Harry Cunningham, what do you think of me?" she asked and then shook her head "On second thought don't answer that" and Harry laughed

"We found some CCTV footage of the twins" Detective Matthews said leaning backward so Harry could get a look at the screen "We pick them up just as they leave their house…."

Harry leant forward and saw on the screen two teenagers running away from the house; Rosie had a head start and was in front of James but he appeared to be faster than her and soon caught up with her

"It gets interesting about here" Matthews told the two pathologists

James had finally caught up with Rosie and had grabbed her by the arm to make her stop. There was a brief struggle with Rosie thrashing around to get James off her but to no avail. Suddenly there was a flurry of activity and Rosie slapped James hard around the face. Both recoiled and stood there for a moment clearly shocked at what had just occurred

"What a backhand!" Harry exclaimed

"Were there any bruises consistent with that struggle?"

Nikki paused for a moment "There were some lighter bruises; it's quite likely that Rosie could have done that. It didn't look like it was too hard but enough to stun him momentarily"

Back on the screen James had grabbed Rosie again and the two of them were standing close together, their foreheads touching. James was mouthing something to Rosie but she was shaking her head wildly. She broke away from his grasp once more and started off down the street again. James took off after her without a seconds thought. A few seconds later they had disappeared out of the cameras gaze

"Rosie seemed very distressed" Nikki said and the two men nodded

"You can see just how close they are" The detective "James took off after her straight away and he was trying to calm her down or something"

"Have you got anything after that?" Harry asked

Matthews shook his head "That's the best we've got. After that they seem to be just out of shot, nothing is very clear. We first see them on Church Street which is where the family home is and the last place we pick them up is Oakley Road which is…" Matthews did a quick calculation "…about forty minutes away from the house"

"And only five minutes from the park" Nikki nodded "I left my cat there when I was called to the scene"

"I hope you didn't double park" Matthews gave a gentle laugh trying to lighten the situation

"At the scene there didn't seem to be much blood so we can probably assume that the twins were dumped there but held and tortured somewhere else" Nikki said and the two men nodded

"It makes sense, the park is too open and public to torture someone and you would hear the screams" Harry said

Matthews sighed "James and Rosie are picked up on Church Street at five o'clock, the last time we see them it's on Oakley Road at twenty to six. They seem to have disappeared off the face of the earth for two weeks and then turn up two weeks later, naked and bound in the park which is in walking distance from the family home. We have two weeks that aren't accounted for. How can two teenagers just fall off the radar for two whole weeks?"

"Whoever held them must be local then" Harry said

Matthews nodded "People rarely kill outside their comfort zones. Whoever did this obviously knew where they could take two children and keep them hidden well out of view"

"There's a lack of defence wounds as well" Nikki commented "It might suggest they knew who it was…"

"Now there's a thought" The detective said looking up at Nikki "We've been thinking that it could have been paedophiles or child abductors but we've never looked at it as an internal family matter"

"Have Rosie given a witness statement?" Harry asked and Matthews shook his head "I'm taking one later today if I can keep her calm for long enough. I can see she gets her temper off her mother"

Nikki nodded as she remember what Matthews had told her about his interview with the North parents

"Doctor Alexander?" a lab technician entered the room and passed her a sheet of paper "The toxicology report has just come through for James North"

"Thank you Liz" Nikki smiled at the lab technician before turning her gaze back to the report "There's a large amount of sedative in James North's blood" she told the two men in the room

"That might help explain the lack of defence wounds as well" Harry said "If they were out of it then they wouldn't have been able to fight back"

"It might also explain how they got them to the park without much of a fight. There were no signs of a struggle at the scene" Matthews said making a note of what Nikki and Harry were telling him "One question though whose injuries were worse?"

Nikki looked at Harry and the two of them communicated silently before Nikki answered "They were both awful" she said "Rosie appeared to have more internal injuries but James had more external injuries. The photographs of Rosie's injuries aren't great but I can probably say that James died first and Rosie's injuries were done over a longer period of time" Matthews nodded

"You suspect the mother" Harry said and Matthews knew it was a statement and not a question

"I suspect everyone right now. Mrs North hates her daughter so she has motive for hurting Rosie but I can't see her killing her favourite child James. Rosie on the other hand has motive for killing James either out of rage or jealously or both but I can't see how she could have inflicted those injuries on herself. Mr North clearly loves both of his children but he seems to have turned a blind eye for his wife's animosity towards Rosie maybe he thought he could resolve the conflict by removing the problem; the children, maybe he went to teach them a lesson or scare them and it went too far. Everyone has a motive in this case but the own obvious witness we have right now is Rosie and goodness knows what games she's playing with us…"

Author's note: Another chapter to make up for not updating yesterday

So who do you suspect? *hint* I can tell you that it is a character you have already been introduced to. It won't just be someone I make up at the last minute